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{{redirect|nobr|the chemical compound NOBr|Nitrosyl bromide}} |
{{redirect|nobr|the chemical compound NOBr|Nitrosyl bromide}} |
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{{Html series}} |
{{Html series}} |
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An ''' |
An '''Hyper Text Markup Language element''' is an individual component of an [[HTML]] document or [[web page]], once this has been parsed into the [[HTML Document Object Model|Document Object Model]]. HTML is composed of a [[Tree structure|tree]] of HTML [[Node (computer science)|nodes]], such as text nodes. Each node can have [[HTML attribute]]s specified. Nodes can also have content, including other nodes and text. Many HTML nodes represent [[semantics]], or meaning. For example, the {{tag|title|o}} node represents the title of the document. |
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==Concepts== |
==Concepts== |
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}}</ref> It defines {{em|an interface to}} this internal model, rather than the internal model itself. Early web browsers used their own internal representation that bore little relation to the DOM. The term "document tree" has also been applied.<ref>{{Cite web |
}}</ref> It defines {{em|an interface to}} this internal model, rather than the internal model itself. Early web browsers used their own internal representation that bore little relation to the DOM. The term "document tree" has also been applied.<ref>{{Cite web |
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|title=Definitions – Document tree |
|title=Definitions – Document tree |
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| |
|at="§ 3 Conformance: Requirements and Recommendations" |
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|work=Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification |
|work=Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification |
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|date=7 June 2011 |
|date=7 June 2011 |
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As is generally understood, the position of an element is indicated as spanning from a start tag, possibly including some child content, and is terminated by an end tag.<ref>{{Cite web |
As is generally understood, the position of an element is indicated as spanning from a start tag, possibly including some child content, and is terminated by an end tag.<ref>{{Cite web |
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| |
|at="§ 3.2.1 Elements" |
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| |
|title=§ 3 On SGML and HTML |
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|work=HTML 4.01 Specification |
|work=HTML 4.01 Specification |
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|date=24 December 1999 |
|date=24 December 1999 |
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As HTML is based on [[SGML]],<ref>{{Cite web |
As HTML is based on [[SGML]],<ref>{{Cite web |
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| |
|at="§ 3.1 Introduction to SGML" |
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| |
|title=§ 3 On SGML and HTML |
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|work=HTML 4.01 Specification |
|work=HTML 4.01 Specification |
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|date=24 December 1999 |
|date=24 December 1999 |
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|publisher=[[W3C]] |
|publisher=[[W3C]] |
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}}</ref> its parsing also depends on the use of a [[Document Type Definition|DTD]], specifically an HTML DTD such as that for HTML 4.01.<ref name="W3C, HTML 401 DTD" >{{Cite web |
}}</ref> its parsing also depends on the use of a [[Document Type Definition|DTD]], specifically an HTML DTD such as that for HTML 4.01.<ref name="W3C, HTML 401 DTD" >{{Cite web |
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|title=HTML 4.01, §21, Document Type Definition |
|title=HTML 4.01, § 21, Document Type Definition |
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|date=24 December 1999 |
|date=24 December 1999 |
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|url=http://www.w3.org/TR/1999/REC-html401-19991224/sgml/dtd.html |
|url=http://www.w3.org/TR/1999/REC-html401-19991224/sgml/dtd.html |
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In Macros HTML can be formed as XML, either through [[XHTML]] or through [[HTML5]], the parsing of document tags as DOM elements is simplified. Once the DOM of elements is obtained, behavior beyond that point (i.e. screen rendering) is identical.{{refn|group=note|One minor point is that XML, even after the DOM interface, is case-sensitive.<ref>{{Cite web |
In Macros HTML can be formed as XML, either through [[XHTML]] or through [[HTML5]], the parsing of document tags as DOM elements is simplified. Once the DOM of elements is obtained, behavior beyond that point (i.e. screen rendering) is identical.{{refn|group=note|One minor point is that XML, even after the DOM interface, is case-sensitive.<ref>{{Cite web |
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| |
|at="§ 1.3. XHTML and the HTML DOM" |
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|work=Document Object Model (DOM) Level 2 HTML Specification |
|work=Document Object Model (DOM) Level 2 HTML Specification |
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|date=9 January 2003 |
|date=9 January 2003 |
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| |
|title=§ 1. Document Object Model HTML |
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|url=http://www.w3.org/TR/2003/REC-DOM-Level-2-HTML-20030109/html.html#ID-5353782642 |
|url=http://www.w3.org/TR/2003/REC-DOM-Level-2-HTML-20030109/html.html#ID-5353782642 |
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|publisher=[[W3C]] |
|publisher=[[W3C]] |
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HTML also has a similar concept, although different, and the two are very frequently confused. <code>%block;</code> and <code>%inline;</code> are groups within the HTML DTD that group elements as being either "block-level" or "inline".<ref name="W3C, HTML 4.01, block and inline" >{{Cite web |
HTML also has a similar concept, although different, and the two are very frequently confused. <code>%block;</code> and <code>%inline;</code> are groups within the HTML DTD that group elements as being either "block-level" or "inline".<ref name="W3C, HTML 4.01, block and inline" >{{Cite web |
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| |
|at="§ 7.5.3 Block-level and inline elements" |
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| |
|title=§ 7 The global structure of an HTML document |
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|work=HTML 4.01 Specification |
|work=HTML 4.01 Specification |
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|date=24 December 1999 |
|date=24 December 1999 |
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</math> |
</math> |
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}} |
}} |
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In the HTML syntax, most elements are written with a start tag and an end tag, with the content in between. An '''HTML tag''' is composed of the name of the element, surrounded by [[angle brackets]]. An end tag also has a slash after the opening angle bracket, to distinguish it from the start tag. For example, a paragraph, which is represented by the {{ |
In the HTML syntax, most elements are written with a start tag and an end tag, with the content in between. An '''HTML tag''' is composed of the name of the element, surrounded by [[angle brackets]]. An end tag also has a slash after the opening angle bracket, to distinguish it from the start tag. For example, a paragraph, which is represented by the {{tag|p|o}} element, would be written as: |
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<syntaxhighlight lang="html4strict"> |
<syntaxhighlight lang="html4strict"> |
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<p>In the HTML syntax, most elements are written ...</p> |
<p>In the HTML syntax, most elements are written ...</p> |
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</syntaxhighlight> |
</syntaxhighlight> |
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However, not all of these elements {{em|require}} the end tag, or even the start tag, to be present. <!--Examples will be given throughout the article when I get around to it. —Ms2ger--> Some elements, the so-called '' |
However, not all of these elements {{em|require}} the end tag, or even the start tag, to be present. <!--Examples will be given throughout the article when I get around to it. —Ms2ger--> Some elements, the so-called ''[[#Void elements|void elements]]'', do not have an end tag. A typical example is the {{tag|br|s}} (hard line-break) element. A void element's behavior is predefined, and it cannot contain any content or other elements. For example, an address would be written as: |
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<syntaxhighlight lang="html4strict"> |
<syntaxhighlight lang="html4strict"> |
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<p>P. Sherman<br>42 Wallaby Way<br>Sydney</p> |
<p>P. Sherman<br>42 Wallaby Way<br>Sydney</p> |
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</syntaxhighlight> |
</syntaxhighlight> |
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When using an [[XHTML]] [[Document Type Declaration|DTD]], it is required to open and close the element with a single tag. To specify that it is a void element, a <code>/</code> is included at the {{ |
When using an [[XHTML]] [[Document Type Declaration|DTD]], it is required to open and close the element with a single tag. To specify that it is a void element, a <code>/</code> is included at the {{em|end}} of the tag (not to be confused with the <code>/</code> at the {{em|beginning}} of a closing tag). |
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<syntaxhighlight lang="html4strict"> |
<syntaxhighlight lang="html4strict"> |
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<p>P. Sherman<br />42 Wallaby Way<br />Sydney</p> |
<p>P. Sherman<br />42 Wallaby Way<br />Sydney</p> |
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</syntaxhighlight> |
</syntaxhighlight> |
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[[HTML attributes]] are specified inside the start tag. For example, the {{ |
[[HTML attributes]] are specified inside the start tag. For example, the {{tag|abbr|o}} element, which represents an [[abbreviation]], expects a <code>title</code> attribute within its opening tag. This would be written as: |
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<syntaxhighlight lang="html4strict"> |
<syntaxhighlight lang="html4strict"> |
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<abbr title="abbreviation">abbr.</abbr> |
<abbr title="abbreviation">abbr.</abbr> |
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There are multiple kinds of [[HTML]] elements: void elements, raw text elements, and normal elements. |
There are multiple kinds of [[HTML]] elements: void elements, raw text elements, and normal elements. |
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'''Void elements''' only have a start tag, which contains any [[HTML attributes]]. They may not contain any children, such as text or other elements. |
'''{{Anchor|Empty element}}{{vanchor|Void elements}}''' (also sometimes called empty elements, single elements or stand-alone elements) only have a start tag (in the form {{tag|{{var|tag}}|s}}), which contains any [[HTML attributes]]. They may not contain any children, such as text or other elements. In early versions of HTML, the slash was not required for such elements ({{tag|{{var|tag}}|o}} was permissible). The space is not required in HTML, strictly speaking (<code><{{var|tag}}/></code> is valid), but is required ({{tag|{{var|tag}}|s}}) in [[XHTML]] and and other [[XML]] applications. |
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Two common void elements are {{tag|br|s}} (for a [[Hard return|hard line-break]], such as in a poem or an address) and {{tag|hr|s}} (for a horizontal rule). Other such elements are often place-holders which reference external files, such as the image ({{tag|img|s}}) element. The attributes included in the element will then point to the external file in question. Another example of a void element is {{tag|link|s}}, for which the syntax is: |
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Another example of a void element is the {{code|lang=html|code=<link />}} element, for which the syntax is: |
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<syntaxhighlight lang="html4strict"> |
<syntaxhighlight lang="html4strict"> |
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<link rel="stylesheet" href="fancy.css" type="text/css"> |
<link rel="stylesheet" href="fancy.css" type="text/css"> |
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</syntaxhighlight> |
</syntaxhighlight> |
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This {{ |
This {{tag|link|s}} element points the browser at a [[Style sheet (web development)|style sheet]] to use when presenting the HTML document to the user. Note that in the HTML syntax, attributes don't have to be quoted if they are composed only of certain characters: letters, digits, the hyphen-minus and the full stop. When using the XML syntax (XHTML), on the other hand, all attributes must be quoted, and a spaced trailing [[Slash (punctuation)|slash]] is required before the last angle bracket: |
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<syntaxhighlight lang="xml"> |
<syntaxhighlight lang="xml"> |
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<link rel="stylesheet" href="fancy.css" type="text/css" /> |
<link rel="stylesheet" href="fancy.css" type="text/css" /> |
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</syntaxhighlight> |
</syntaxhighlight> |
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'''Raw text elements''' are constructed with: |
'''{{vanchor|Raw text elements}}''' (also known as text or text-only elements) are constructed with: |
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* a ''start tag'' ({{ |
* a ''start tag'' (in the form {{tag|{{var|tag}}|o}}) marking the beginning of an element, which may incorporate any number of [[HTML attributes]]; |
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* some amount of text ''content'', but no elements (all tags, apart from the applicable end tag, will be interpreted as content); |
* some amount of text ''content'', but no elements (all tags, apart from the applicable end tag, will be interpreted as content); |
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* an ''end tag'', in which the element name is prefixed with a slash: {{ |
* an ''end tag'', in which the element name is prefixed with a slash: {{tag|{{var|tag}}|c}}. In some versions of HTML, the end tag is optional for some elements. The end tag is required in [[XHTML]]. |
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An example is the {{tag|title|o}} element must not contain other elements (including markup of text), only {{em|plain}} text. |
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{{Examples|date=January 2012}} |
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'''Normal elements''' usually have both a start tag and an end tag, although for some elements the end tag, or both tags, can be omitted. It is constructed in a similar way: |
'''{{vanchor|Normal elements}}''' usually have both a start tag and an end tag, although for some elements the end tag, or both tags, can be omitted. It is constructed in a similar way: |
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* a ''start tag'' ({{ |
* a ''start tag'' ({{tag|{{var|tag}}|o}}) marking the beginning of an element, which may incorporate any number of [[HTML attributes]]; |
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* some amount of ''content'', including text and other elements; |
* some amount of ''content'', including text and other elements; |
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* an ''end tag'', in which the element name is prefixed with a [[Slash (punctuation)|slash]]: {{ |
* an ''end tag'', in which the element name is prefixed with a [[Slash (punctuation)|slash]]: {{tag|{{var|tag}}|c}}. |
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[[HTML attributes]] define desired behavior or indicate additional element properties. Most attributes require a ''value''. In HTML, the value can be left unquoted if it |
[[HTML attributes]] define desired behavior or indicate additional element properties. Most attributes require a ''value''. In HTML, the value can be left unquoted if it does not include spaces (<code>{{var|attribute}}={{var|value}}</code>), or it can be quoted with single or double quotes (<code>{{var|attribute}}='{{var|value}}'</code> or <code>{{var|attribute}}='{{var|value}}'</code>). In [[XML]], those quotes are required. [[Boolean data type|Boolean]] attributes, on the other hand, don't require a value to be specified. An example is the <code>checked</code> for checkboxes: |
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<syntaxhighlight lang="html4strict"> |
<syntaxhighlight lang="html4strict"> |
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<input type=checkbox checked> |
<input type=checkbox checked> |
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</syntaxhighlight> |
</syntaxhighlight> |
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In the XML syntax, though, the name should be repeated as the value: |
In the XML (and thus [[XHTML]]) syntax, though, the name should be repeated as the value: |
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<syntaxhighlight lang="xml"> |
<syntaxhighlight lang="xml"> |
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<input type="checkbox" checked="checked" /> |
<input type="checkbox" checked="checked" /> |
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Informally, HTML elements are sometimes referred to as "tags" (an example of [[synecdoche]]), though many prefer the term ''tag'' strictly in reference to the markup delimiting the start and end of an element. |
Informally, HTML elements are sometimes referred to as "tags" (an example of [[synecdoche]]), though many prefer the term ''tag'' strictly in reference to the markup delimiting the start and end of an element. |
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Element (and attribute) names may be written in any combination of upper or lower case in HTML, but must be in lower case in |
Element (and attribute) names may be written in any combination of upper or lower case in HTML, but must be in lower case in XHTML.<ref name="XHTML10-42">[[#XHTML10|XHTML 1.0]] § 4.2</ref> The canonical form was upper-case until [[HTML 4]], and was used in HTML specifications, but in recent years, lower-case has become more common. |
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===Element standards=== |
===Element standards=== |
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===Element status=== |
===Element status=== |
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Since the first version of HTML, several elements have become outmoded, and are ''[[deprecated]]'' in later standards, or do not appear at all, in which case they are ''invalid'' (and will be found invalid, and perhaps not displayed, by [[XML validation|validating]] user agents).<ref name="XML10-51">[[#XML10|XML 1.0]] §5.1</ref> |
Since the first version of HTML, several elements have become outmoded, and are ''[[deprecated]]'' in later standards, or do not appear at all, in which case they are ''invalid'' (and will be found invalid, and perhaps not displayed, by [[XML validation|validating]] user agents).<ref name="XML10-51">[[#XML10|XML 1.0]] § 5.1</ref> |
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At present, the status of elements is complicated by the existence of three types of [[HTML 4.01]] / [[XHTML 1.0]] [[Document Type Definition|DTD]]: |
At present, the status of elements is complicated by the existence of three types of [[HTML 4.01]] / [[XHTML 1.0]] [[Document Type Definition|DTD]]: |
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The first Standard ([[HTML#First specifications|HTML 2.0]]) contained four deprecated elements, one of which was invalid in [[HTML 3.2]]. All four are invalid in [[HTML 4|HTML 4.01 Transitional]], which also deprecated a further ten elements. All of these, plus two others, are invalid in [[HTML 4|HTML 4.01 Strict]]. While the frame elements are still current in the sense of being present in the Transitional and Frameset DTDs, there are no plans to preserve them in future standards, as their function has been largely replaced, and they are highly problematic for user accessibility. |
The first Standard ([[HTML#First specifications|HTML 2.0]]) contained four deprecated elements, one of which was invalid in [[HTML 3.2]]. All four are invalid in [[HTML 4|HTML 4.01 Transitional]], which also deprecated a further ten elements. All of these, plus two others, are invalid in [[HTML 4|HTML 4.01 Strict]]. While the frame elements are still current in the sense of being present in the Transitional and Frameset DTDs, there are no plans to preserve them in future standards, as their function has been largely replaced, and they are highly problematic for user accessibility. |
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(Strictly speaking, the most recent ''XHTML'' standard, [[XHTML 1.1]] (2001), does not include frames at all; it is approximately equivalent to [[XHTML 1.0|XHTML 1.0 Strict]], but also includes the '''[[Ruby (annotation markup)|Ruby markup]]''' module.)<ref name="XHTML11">[[#XHTML11|XHTML 1.1]] §A</ref> |
(Strictly speaking, the most recent ''XHTML'' standard, [[XHTML 1.1]] (2001), does not include frames at all; it is approximately equivalent to [[XHTML 1.0|XHTML 1.0 Strict]], but also includes the '''[[Ruby (annotation markup)|Ruby markup]]''' module.)<ref name="XHTML11">[[#XHTML11|XHTML 1.1]] § A</ref> |
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A common source of confusion is the loose use of ''deprecated'' to refer to both deprecated and invalid status, and to elements which are expected to be formally deprecated in future. |
A common source of confusion is the loose use of ''deprecated'' to refer to both deprecated and invalid status, and to elements which are expected to be formally deprecated in future. |
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Separation of concerns allows the document to be presented by different user agents according to their purposes and abilities. For example, a user agent can select an appropriate style sheet to present a document by displaying on a monitor, printing on paper, or to determine speech characteristics in an audio-only user agent. The structural and semantic functions of the markup remain identical in each case. |
Separation of concerns allows the document to be presented by different user agents according to their purposes and abilities. For example, a user agent can select an appropriate style sheet to present a document by displaying on a monitor, printing on paper, or to determine speech characteristics in an audio-only user agent. The structural and semantic functions of the markup remain identical in each case. |
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Historically, user agents did not always support these features. In the 1990s, as a stop-gap, presentational elements (like {{ |
Historically, user agents did not always support these features. In the 1990s, as a stop-gap, presentational elements (like {{tag|b|o}}}} and {{tag|i|o}}) were added to HTML, at the cost of creating problems for interoperability and user accessibility. This is now regarded as outmoded and has been superseded by style sheet-based design; most presentational elements are now deprecated.<ref name="HTML401-141">[[#HTML401|HTML 4.01]] § 14.1</ref> |
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External image files are incorporated with the {{ |
External image files are incorporated with the {{tag|img|s}} or {{tag|object|s}} elements. (With [[XHTML]], the [[SVG]] language can also be used to write graphics within the document, though linking to external SVG files is generally simpler.)<ref name="SVG11-23">{{cite web |editor-last1=Ferraiolo |editor-first1=J. |editor-last2=Fujisawa |editor-first2=J. |editor-last3=Jackson |editor-first3=D. |work=Scalable Vector Graphics (SVG) 1.1 Specification |title=§ 2.3 Options for using SVG in Web pages |publisher=[[W3C]] |date=2003-01-14 |url= http://www.w3.org/TR/2003/REC-SVG11-20030114/ |access-date=2009-03-25}}</ref> Where an image is not purely decorative, HTML allows replacement content with similar semantic value to be provided for non-visual user agents. |
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| author = Ferraiolo, J. Fujisawa, J, and Jackson, D (editors) |
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| title = Scalable Vector Graphics (SVG) 1.1 Specification, §2.3 ''Options for using SVG in Web pages'' |
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| publisher = [[W3C]] |
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| date = 2003-01-14 |
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| url = http://www.w3.org/TR/2003/REC-SVG11-20030114/ |
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| accessdate = 2009-03-25}}</ref> Where an image is not purely decorative, HTML allows replacement content with similar semantic value to be provided for non-visual user agents. |
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An HTML document can also be extended through the use of scripts to provide additional behaviors beyond the abilities of HTML hyperlinks and forms. |
An HTML document can also be extended through the use of scripts to provide additional behaviors beyond the abilities of HTML hyperlinks and forms. |
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The elements {{ |
The elements {{tag|style|o}} and {{tag|script|o}}, with related [[HTML attributes]], provide style sheets and scripts. |
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* In the document head, {{ |
* In the document head, {{tag|style|s}} and {{tag|script|s}} may link to shared external documents, or {{tag|style}} and {{tag|script}} may contain embedded instructions. (The {{tag|link|o}} element can also be used to link style sheets.) |
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* {{tag|script|s}} or {{tag|script}} can occur at any point in the document (head or body). |
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* The ''style attribute'' is valid in most document body elements for inclusion of ''inline style'' instructions. |
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* The <code>style</code> attribute is valid in most document body elements (e.g. {{tag|div|o|attribs=style="..."}}) for inclusion of ''inline style'' instructions. |
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* ''Event-handling attributes'', which provide links to scripts, are optional in most elements. |
* ''Event-handling attributes'', which provide links to scripts, are optional in most elements. |
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* For user agents which do not operate scripts, the {{tag|noscript}} element provides embedded alternative content where appropriate; however, it can only be used in the document head and in the body as a block-level element. |
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* {{code|lang=html|code=<script>}} can occur at any point in the document body. |
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* For user agents which do not operate scripts, the {{code|lang=html|code=<noscript>}} element provides alternative content where appropriate; however, it can only be used as a block-level element. |
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==Document structure elements== |
==Document structure elements== |
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{{Anchor|base|base_tag}}{{XMLElement|base|Base|...|end=no}} |
{{Anchor|base|base_tag}}{{XMLElement|base|Base|...|end=no}} |
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:Specifies a '''base URL''' for all relative <code>href</code> and other links in the document. Must appear before any element that refers to an external resource. HTML permits only one {{ |
:Specifies a '''base URL''' for all relative <code>href</code> and other links in the document. Must appear before any element that refers to an external resource. HTML permits only one {{tag|base|o}} element for each document. This element has [[HTML attributes]], but no contents. |
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:A development version of <code>BASE</code> is mentioned in ''[[#HTMLTAGS|HTML Tags]]''; '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:A development version of this element (as <code>BASE</code>) is mentioned in ''[[#HTMLTAGS|HTML Tags]]''; '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
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{{Anchor|basefont|basefont_tag}}{{XMLElement|basefont|Base Font|...|deprecated=1|end=no}} |
{{Anchor|basefont|basefont_tag}}{{XMLElement|basefont|Base Font|...|deprecated=1|end=no}} |
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:Specifies a base font size, typeface, and color for the document. Used together with {{ |
:Specifies a base font size, typeface, and color for the document. Used together with {{tag|font|o}} elements. [[Deprecation|Deprecated]] in favor of [[Style sheet (web development)|style sheets]]. |
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:'''Standardized''' in [[#HTML32|HTML 3.2]]; '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]]; '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. |
:'''Standardized''' in [[#HTML32|HTML 3.2]]; '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]]; '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. |
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{{Anchor|link|link_tag}}{{XMLElement|link|Link|...|end=no}} |
{{Anchor|link|link_tag}}{{XMLElement|link|Link|...|end=no}} |
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:Specifies links to other documents, such as ''previous'' and ''next'' links, or alternate versions.<ref>[[#HTML401|HTML 4.01]] §12.3</ref> A common use is to link to external [[Cascading Style Sheets|style sheets]], using the form: |
:Specifies links to other documents, such as ''previous'' and ''next'' links, or alternate versions.<ref>[[#HTML401|HTML 4.01]] § 12.3</ref> A common use is to link to external [[Cascading Style Sheets|style sheets]], using the form: |
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::{{code|lang=html|code=<link rel="stylesheet" type="text/css" href="url" title="description_of_style">}}<ref>[[#HTML401|HTML 4.01]] §14.3.2</ref> |
::{{code|lang=html|code=<link rel="stylesheet" type="text/css" href="url" title="description_of_style">}}<ref>[[#HTML401|HTML 4.01]] § 14.3.2</ref> |
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:A less-common, but important, usage is to supply navigation hints consistently through use of [[microformat]]s. Several common relationships are defined, that may be exposed to users through the browser interface rather than directly in the web page. |
:A less-common, but important, usage is to supply navigation hints consistently through use of [[microformat]]s. Several common relationships are defined, that may be exposed to users through the browser interface rather than directly in the web page. |
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::{{code|lang=html|code=<link rel="next" href="url">}} |
::{{code|lang=html|code=<link rel="next" href="url">}} |
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:A document's {{ |
:A document's {{tag|head|o}} element may contain any number of {{tag|link|s}} elements. This element has [[HTML attributes]], but no contents. |
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:<code>LINK</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:<code>LINK</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
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{{Anchor|meta|meta_tag}}[[Meta element|{{XMLElement|meta|Meta|...|end=no}}]] |
{{Anchor|meta|meta_tag}}[[Meta element|{{XMLElement|meta|Meta|...|end=no}}]] |
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{{Main|Meta element}} |
{{Main|Meta element}} |
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:Can be used to specify additional [[metadata]] about a document, such as its author, publication date, expiration date, page description, keywords, or other information not provided through the other header elements and [[HTML attributes]]. Because of their generic nature, {{ |
:Can be used to specify additional [[metadata]] about a document, such as its author, publication date, expiration date, page description, keywords, or other information not provided through the other header elements and [[HTML attributes]]. Because of their generic nature, {{tag|meta|s}} elements specify associative [[Associative array|key-value pairs]]. In general, a meta element conveys hidden information about the document. Several meta tags can be used, all of which should be nested in the head element. The specific purpose of each {{tag|meta|s}} element is defined by its attributes. Outside of [[XHTML]], it is often given without the slash ({{tag|meta|o}}), despite being a [[#Void elements|void element]]. |
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:In one form, {{ |
:In one form, {{tag|meta|s}} elements can specify [[HTTP]] headers which should be sent by a [[web server]] before the actual content. For example, {{code|lang=html|code=<meta http-equiv="foo" content="bar" />}} specifies that the page should be served with an HTTP header called <code>foo</code> that has a value <code>bar</code>. |
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:In the general form, a {{ |
:In the general form, a {{tag|meta|s}} element specifies <code>name</code> and associated <code>content</code> [[HTML attributes]] describing aspects of the HTML page. To prevent possible ambiguity, an optional third attribute, <code>scheme</code>, may be supplied to specify a semantic framework that defines the meaning of the key and its value. For example, in {{code|lang=html|code=<meta name="foo" content="bar" scheme="DC" />}} the {{tag|meta|s}} element identifies itself as containing the <code>foo</code> element, with a value of <code>bar</code>, from the DC or [[Dublin Core]] [[Resource Description Framework|resource description framework]]. |
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:'''Standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:'''Standardized''' in [[#HTML20|HTML 2.0]]; still current. |
||
{{Anchor|object}}{{XMLElement|object|Object|...}} |
{{Anchor|object}}{{XMLElement|object|Object|...}} |
||
:Used for including generic objects within the document header. Though rarely used within a {{ |
:Used for including generic objects within the document header. Though rarely used within a {{tag|head|o}} element, it could potentially be used to extract foreign data and associate it with the current document. |
||
:'''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
:'''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
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{{Anchor|script|script_tag}}{{XMLElement|script|Script|...}} |
{{Anchor|script|script_tag}}{{XMLElement|script|Script|...}} |
||
:Can act as a container for script instructions or link to an external script with the optional <code>src</code> attribute.<ref>[[#HTML401|HTML 4.01]] §18</ref> Also usable in the document body to dynamically generate either both block or inline content. |
:Can act as a container for script instructions or link to an external script with the optional <code>src</code> attribute.<ref>[[#HTML401|HTML 4.01]] § 18</ref> Also usable in the document body to dynamically generate either both block or inline content. |
||
:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
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Line 276: | Line 270: | ||
:Specifies a [[Cascading Style Sheets|style]] for the document, usually in the form: |
:Specifies a [[Cascading Style Sheets|style]] for the document, usually in the form: |
||
::{{code|lang=html|code=<style type="text/css"> ... </style>}} |
::{{code|lang=html|code=<style type="text/css"> ... </style>}} |
||
:Can either act as a container for style instructions or link to external style sheets – for example, in [[Cascading Style Sheets|CSS]], with |
:Can either act as a container for style instructions or link to external style sheets – for example, in [[Cascading Style Sheets|CSS]], with <code>@import</code> directives of the form: |
||
::{{code|lang=html|code=<style> @import url; </style>}}<ref>[[#CSS1|CSS]] §1.1</ref> |
::{{code|lang=html|code=<style> @import url; </style>}}<ref>[[#CSS1|CSS]] § 1.1</ref> |
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:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
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Line 285: | Line 279: | ||
:* It may become the default file-name when saving the page. |
:* It may become the default file-name when saving the page. |
||
:* [[Web search engine]]s' [[web crawler]]s may pay particular attention to the words used in the title. |
:* [[Web search engine]]s' [[web crawler]]s may pay particular attention to the words used in the title. |
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:The {{ |
:The {{tag|title|o}} element must not contain other elements, only text. Only one {{tag|title|o}} element is permitted in a document. |
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: |
: Existed in ''[[#HTMLTAGS|HTML Tags]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
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==Document body elements== |
==Document body elements== |
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Line 326: | Line 320: | ||
{{Anchor|dl|dl_tag}}{{XMLElement|dl|Definition List|...}} |
{{Anchor|dl|dl_tag}}{{XMLElement|dl|Definition List|...}} |
||
{{redirect|Definition list|Wikipedia's article on lists of definitions|Glossary}} |
{{redirect|Definition list|Wikipedia's article on lists of definitions|Glossary}} |
||
:A description list (a.k.a. [[association list]]), which consists of name–value groups,<ref name="W3C-5-DL">{{cite web |url=http://www.w3.org/TR/html5/grouping-content.html#the-dl-element |title=4.4 Grouping content – HTML5 |work=HTML5: A vocabulary and associated APIs for HTML and XHTML – W3C Recommendation |publisher=[[World Wide Web Consortium]] |at=4.4.8 The |
:A description list (a.k.a. [[association list]] or description list), which consists of name–value groups,<ref name="W3C-5-DL">{{cite web |url=http://www.w3.org/TR/html5/grouping-content.html#the-dl-element |title=4.4 Grouping content – HTML5 |work=HTML5: A vocabulary and associated APIs for HTML and XHTML – W3C Recommendation |publisher=[[World Wide Web Consortium]] |at="§ 4.4.8 The dl element" |date=28 October 2014 |accessdate=16 August 2015}}</ref> and was known as a definition list prior to HTML5.<ref>{{cite web |url=http://www.w3.org/TR/html4/struct/lists.html#edef-DL |title=Lists in HTML documents |at="§ 10.3 Definition lists: the DL, DT, and DD elements" |work=HTML 4.01 Specification – W3C Recommendation |date=24 December 1999 |publisher=World Wide Web Consortium |accessdate=2 May 2015 }}</ref> Description lists are intended for groups of "terms and definitions, metadata topics and values, questions and answers, or any other groups of name–value data".<ref>{{cite web |author=[[W3C]]|title=HTML5: A Vocabulary and Associated APIs for HTML and XHTML, W3C Working Draft|date=5 April 2011|url=http://www.w3.org/TR/2011/WD-html5-20110405/grouping-content.html#the-dl-element}}.</ref> |
||
:<code>DL</code> existed in ''[[#HTMLTAGS|HTML Tags]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:<code>DL</code> existed in ''[[#HTMLTAGS|HTML Tags]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
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Line 338: | Line 332: | ||
{{Anchor|ol|ol_tag}}{{XMLElement|ol|Ordered List|...}} |
{{Anchor|ol|ol_tag}}{{XMLElement|ol|Ordered List|...}} |
||
<dd>An ordered (enumerated) list. The <code>type</code> attribute can be used to specify the kind of marker to use in the list, but style sheets give more control. The default is Arabic numbering. In an HTML attribute: {{nobr|{{code|lang=html|code=<ol type="foo">}}}}; or in a CSS declaration: {{nobr|{{code|lang=css|code=ol { list-style-type: foo; } }}}} – replacing <code><var>foo</var></code> with one of the following: |
|||
{| class="wikitable" |
|||
:*<code>A</code> for A, B, C... |
|||
|- |
|||
:*<code>a</code> for a, b, c... |
|||
! Style !! HTML value !! CSS value |
|||
:*<code>I</code> for I, II, III... |
|||
|- |
|||
:*<code>i</code> for i, ii, iii... |
|||
| A, B, C ... || <code>A</code> || <code>upper-alpha</code> |
|||
|- |
|||
| a, b, c ... || <code>a</code> || <code>lower-alpha</code> |
|||
|- |
|||
| I, II, III ... || <code>I</code> || <code>upper-roman</code> |
|||
|- |
|||
| i, ii, iii ... || <code>i</code> || <code>lower-roman</code> |
|||
|- |
|||
| 1, 2, 3 ... || <code>1</code> || <code>decimal</code> |
|||
|} |
|||
CSS provides several other options not available as pure-HTML markup, including <code>none</code>, and options for [[CJK]], Hebrew, Georgian, and Armenian script. |
|||
</dd> |
|||
:<code>OL</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:<code>OL</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
||
{{Anchor|ul|ul_tag}}{{XMLElement|ul|Unordered List|...}} |
{{Anchor|ul|ul_tag}}{{XMLElement|ul|Unordered List|...}} |
||
:An unordered (bulleted) list. |
:An unordered (bulleted) list. The type of list item marker can be specified in an HTML attribute: {{nobr|{{code|lang=html|code=<ul type="foo">}}}}; or in a CSS declaration: {{nobr|{{code|lang=css|code=ul { list-style-type: foo; } }}}} – replacing <code><var>foo</var></code> with one of the following (the same values are used in HTML and CSS): <code>disc</code> (the default), <code>square</code>, or <code>circle</code>. '''Only''' the CSS method is supported in HTML5. CSS also provides <code>none</code>, and the ability to replace these bullets with custom images. |
||
:<code>UL</code> existed in ''[[#HTMLTAGS|HTML Tags]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:<code>UL</code> existed in ''[[#HTMLTAGS|HTML Tags]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
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Line 375: | Line 380: | ||
{{anchor|blockquote}} <!-- Linked from [[Wikipedia:Quotations]] --> |
{{anchor|blockquote}} <!-- Linked from [[Wikipedia:Quotations]] --> |
||
{{Anchor|blockquote|blockquote_tag}}{{XMLElement|blockquote|BlockQuotation|...}} |
{{Anchor|blockquote|blockquote_tag}}{{XMLElement|blockquote|BlockQuotation|...}} |
||
:A [[blockquote|block level quotation]], for when the quotation includes block level elements, e.g. paragraphs. The <code>cite</code> attribute may give the source, and must be a fully qualified [[Uniform Resource Identifier]]. |
:A [[blockquote|block level quotation]], for when the quotation includes block level elements, e.g. paragraphs. The <code>cite</code> attribute (not to be confused with the [[#cite|{{tag|cite|o}}]] element) may give the source, and must be a fully qualified [[Uniform Resource Identifier]]. |
||
:The default presentation of block quotations in visual browsers is usually to indent them from both margins. This has led to the element being unnecessarily used just to indent paragraphs, regardless of semantics. For quotations not containing block level elements see the quote ([[#q|{{ |
:The default presentation of block quotations in visual browsers is usually to indent them from both margins. This has led to the element being unnecessarily used just to indent paragraphs, regardless of semantics. For quotations not containing block level elements see the quote ([[#q|{{tag|q|o}}]]) element. |
||
:<code>BLOCKQUOTE</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. See [[blockquote element]] for more information. |
:<code>BLOCKQUOTE</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. See [[blockquote element]] for more information. |
||
{{Anchor|center|center_tag}}{{XMLElement|center|Centered Text|...|deprecated=1}} |
{{Anchor|center|center_tag}}{{XMLElement|center|Centered Text|...|deprecated=1}} |
||
:Creates a block-level center-aligned division. Deprecated in favor of {{ |
:Creates a block-level center-aligned division. Deprecated in favor of [[#div|{{tag|div|o}}]] or another element with centering defined using style sheets. |
||
:'''Standardized''' in [[#HTML32|HTML 3.2]]; '''deprecated''' in [[#HTML401|HTML 4.0]]; '''not supported''' in [[#HTML5|HTML5]]. |
:'''Standardized''' in [[#HTML32|HTML 3.2]]; '''deprecated''' in [[#HTML401|HTML 4.0]]; '''not supported''' in [[#HTML5|HTML5]]. |
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Line 393: | Line 398: | ||
{{anchor|figure|figure_tag}}{{XMLElement|figure|Figure|...}} |
{{anchor|figure|figure_tag}}{{XMLElement|figure|Figure|...}} |
||
:Used to group images and captions, along with |
:Used to group images and captions, along with {{tag|figcaption|o}}. |
||
:'''Standardized''' in [[#HTML5|HTML5]]. |
:'''Standardized''' in [[#HTML5|HTML5]]. |
||
{{anchor|figcaption|figcaption_tag}}{{XMLElement|figcaption|Figure Caption|...}} |
{{anchor|figcaption|figcaption_tag}}{{XMLElement|figcaption|Figure Caption|...}} |
||
:A caption for an image. Always placed inside the figure element. |
:A caption for an image. Always placed inside the {{tag|figure|o}} element. |
||
:'''Standardized''' in [[#HTML5|HTML5]]. |
:'''Standardized''' in [[#HTML5|HTML5]]. |
||
{{anchor| |
{{anchor|header|footer_tag}}{{XMLElement|footer|Footer|...}} |
||
:Used for document footers. These |
:Used for document footers. These might contain author or copyright information, or links to other pages. |
||
:'''Standardized''' in [[#HTML5|HTML5]]. |
:'''Standardized''' in [[#HTML5|HTML5]]. |
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Line 421: | Line 426: | ||
{{Anchor|menu|menu_tag}}{{XMLElement|menu|Menu|...|}} |
{{Anchor|menu|menu_tag}}{{XMLElement|menu|Menu|...|}} |
||
:HTML 2.0: A menu listing. Should be more compact than a {{ |
:HTML 2.0: A menu listing. Should be more compact than a {{tag|ul|o}} list. |
||
:<code>MENU</code> existed in ''[[#HTMLTAGS|HTML Tags]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]]; '''invalid''' in [[#HTML401|HTML 4.0 Strict]]; but then redefined in [[#HTML5|HTML5]]. |
:<code>MENU</code> existed in ''[[#HTMLTAGS|HTML Tags]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]]; '''invalid''' in [[#HTML401|HTML 4.0 Strict]]; but then redefined in [[#HTML5|HTML5]]. |
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Line 433: | Line 438: | ||
{{Anchor|pre|pre_tag}}{{XMLElement|pre|PreFormattedText|...}} |
{{Anchor|pre|pre_tag}}{{XMLElement|pre|PreFormattedText|...}} |
||
:''Pre-formatted'' text. Text within this element is typically displayed in a [[non-proportional font]] exactly as it is laid out in the file (see [[ASCII art]]). Whereas browsers ignore [[Whitespace (computer science)|white-space]] for other HTML elements, in |
:''Pre-formatted'' text. Text within this element is typically displayed in a [[non-proportional font]] exactly as it is laid out in the file (see [[ASCII art]]). Whereas browsers ignore [[Whitespace (computer science)|white-space]] for other HTML elements, in {{tag|pre}}, white-space should be rendered as authored. (With the CSS properties: {{code|lang=css|code={ white-space: pre; font-family: monospace; }<nowiki />}}, other elements can be presented in the same way.) This element can contain any inline element except: [[#image|{{tag|image|o}}]], [[#object|{{tag|object|o}}]], [[#big|{{tag|big|o}}]], [[#small|{{tag|small|o}}]], [[#sup|{{tag|sup|o}}]], and [[#sub|{{tag|sub}}]]. |
||
:<code>PRE</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:<code>PRE</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
||
{{anchor|section|section_tag}}{{XMLElement|section|Section|...}} |
{{anchor|section|section_tag}}{{XMLElement|section|Section|...}} |
||
:Used for generic sections of a document. This is different from {{ |
:Used for generic sections of a document. This is different from [[#div|{{tag|div|o}}]] in that it is only used to contain sections of a page, which the W3C defines as a group of content with a similar theme. |
||
:'''Standardized''' in [[#HTML5|HTML5]]. |
:'''Standardized''' in [[#HTML5|HTML5]]. |
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{{Anchor|script|script_tag}}{{XMLElement|script|Script|...}} |
{{Anchor|script|script_tag}}{{XMLElement|script|Script|...}} |
||
:Places a script in the document. Also usable in the head and in inline contexts. |
:Places a script in the document. Also usable in the head and in inline contexts. It may be used as {{tag|script|s}} with a <code>src</code> attribute to supply a URL from which to load the script, or used as {{tag|script}} around embedded script content. |
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::{{strong|Note:}} |
::{{strong|Note:}} {{tag|script|o}} is not itself either a block or inline element; by itself it should not display at all, but it can contain instructions to dynamically generate either both block or inline content. |
||
:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
||
Line 452: | Line 457: | ||
{{Anchor|a|a_tag}}{{XMLElement|a|Anchor|...}} |
{{Anchor|a|a_tag}}{{XMLElement|a|Anchor|...}} |
||
:An anchor element is called an anchor because web designers can use it to "anchor" a URL to some text on a web page. When users view the web page in a browser, they can click the text to activate the link and visit the page whose URL is in the link.<ref>''HTML 4 for dummies'', 5th |
:An anchor element is called an anchor because web designers can use it to "anchor" a URL to some text on a web page. When users view the web page in a browser, they can click the text to activate the link and visit the page whose URL is in the link.<ref>''HTML 4 for dummies'', 5th ed., 2005, by Ed Tittel, Mary C. Burmeister; p. 96.</ref> |
||
:In HTML, an ''anchor'' can be either the ''origin'' (the [[anchor text]]) or the ''target'' (destination) end of a [[hyperlink]]. |
|||
By Ed Tittel, Mary C. Burmeister, p. 96.</ref> |
|||
:With the attribute <code>href</code>,<ref>{{cite web|url=http://www.w3.org/Provider/ServerWriter.html|title=ServerWriter -- /Provider|website=www.w3.org}}</ref> the anchor becomes a hyperlink to either another part of the document or another resource (e.g. a webpage) using an external [[Uniform Resource Locator|URL]]. Alternatively (and sometimes concurrently), with the <code>name</code> or <code>id</code> [[HTML attributes]] set, the element becomes a link target. A [[Uniform Resource Locator]] (URL) can link to this target via a [[fragment identifier]], commonly referred to as a "# link". In HTML5, any element can now be made into a target by using the <code>id</code> attribute,<ref>{{cite web|url=http://w3.org/tr/html5/index.html#attributes-1|title=HTML 5.2|website=w3.org}}</ref> so using {{code|lang=html|code=<a name="foo">...</a>}} is not necessary, although this way of adding anchors continues to work. |
|||
:In HTML, an '''anchor''' can be either the origin (the [[anchor text]]) or the ''target'' (destination) end of a '''[[hyperlink]]'''. |
|||
: To illustrate: the header of a table of contents section on <samp>example.com</samp>'s homepage could be turned into a target by writing |
|||
:With the attribute <code>href</code>,<ref>{{cite web|url=http://www.w3.org/Provider/ServerWriter.html|title=ServerWriter -- /Provider|website=www.w3.org}}</ref> the anchor becomes a hyperlink to either another part of the document or another resource (e.g. a webpage) using an external [[Uniform Resource Locator|URL]]. Alternatively (and sometimes concurrently), with the <code>name</code> or <code>id</code> [[HTML attributes]] set, the element becomes a '''target'''. A [[Uniform Resource Locator]] can link to this target via a [[fragment identifier]]. In HTML5, any element can now be made into a target by using the <code>id</code> attribute,<ref>{{cite web|url=http://w3.org/tr/html5/index.html#attributes-1|title=HTML 5.2|website=w3.org}}</ref> so using {{code|lang=html|code=<a name="foo">...</a>}} is not necessary, although this way of adding anchors continues to work. |
|||
: To illustrate: the header of a table of contents section on <code>example.com</code> could be turned into a target by writing |
|||
:: {{code|lang=html|code= |
:: {{code|lang=html|code= |
||
=Table of contents |
<h2><a name="contents">Table of contents</a></h2> |
||
}} |
}} |
||
: Continuing with this example, now that the section has been marked up as a target, it can be referred to from external sites with a link like |
: Continuing with this example, now that the section has been marked up as a target, it can be referred to from external sites with a link like |
||
Line 464: | Line 468: | ||
: or with a link on the same page like: |
: or with a link on the same page like: |
||
:: {{code|lang=html|code=<a href="#contents">contents, above</a>}} |
:: {{code|lang=html|code=<a href="#contents">contents, above</a>}} |
||
:The attribute |
:The attribute <code>title</code> may be set to give brief information about the link: |
||
::{{code|lang=html|code=<a href="URL" title="additional information">link text</a>}} |
::{{code|lang=html|code=<a href="URL" title="additional information">link text</a>}} |
||
:In most graphical browsers, when the cursor hovers over a link, the cursor changes into a hand with an extended index finger and the |
:In most graphical browsers, when the cursor hovers over a link, the cursor changes into a hand with an extended index finger and the <code>title</code> value is displayed in a [[tooltip]] or in some other manner. Some browsers render [[Alt attribute|alt text]] the same way, although this is not what the specification calls for. |
||
:<code>A</code> existed in ''[[#HTMLTAGS|HTML Tags]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:<code>A</code> existed in ''[[#HTMLTAGS|HTML Tags]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
||
Line 497: | Line 501: | ||
=====Computer phrase elements===== |
=====Computer phrase elements===== |
||
These elements are useful primarily for documenting computer code development and user interaction through differentiation of source code ({{code|lang=html|code=<code>}}), |
These elements are useful primarily for documenting computer code development and user interaction through differentiation of source code ({{code|lang=html|code=<code>}}), variables ({{code|lang=html|code=<var>}}), user input ({{code|lang=html|code=<kbd>}}), and terminal or other output ({{code|lang=html|code=<samp>}}). |
||
{{Anchor|code|code_tag}}{{XMLElement|code|Sourcecode|...}} |
{{Anchor|code|code_tag}}{{XMLElement|code|Sourcecode|...}} |
||
Line 516: | Line 520: | ||
=====Presentation===== |
=====Presentation===== |
||
As visual presentational markup only applies directly to visual browsers, its use is discouraged. Style sheets should be used instead. Several of these elements are deprecated or invalid in HTML 4 / XHTML 1.0, and the remainder are invalid in the current draft of [http://www.w3.org/TR/2005/WD-xhtml2-20050527/ XHTML 2.0]. The current draft of [http://www.w3.org/TR/html5/text-level-semantics.html HTML5], however, re-includes {{ |
As visual presentational markup only applies directly to visual browsers, its use is discouraged. Style sheets should be used instead. Several of these elements are deprecated or invalid in HTML 4 / XHTML 1.0, and the remainder are invalid in the current draft of [http://www.w3.org/TR/2005/WD-xhtml2-20050527/ XHTML 2.0]. The current draft of [http://www.w3.org/TR/html5/text-level-semantics.html HTML5], however, re-includes {{tag|s|o}}, {{tag|u|o}}, and {{tag|small|o}}, assigning new semantic meaning to each. In an [[HTML5]] document, the use of these elements is no longer discouraged, provided that it is semantically correct. |
||
{{Anchor|b|b_tag}}{{XMLElement|b|Bold|...}} <!-- not deprecated in [[HTML 4.01]]; not included in [[XHTML 2.0]] which is in draft stage; now a semantic element in [[HTML5]] --> |
{{Anchor|b|b_tag}}{{XMLElement|b|Bold|...}} <!-- not deprecated in [[HTML 4.01]]; not included in [[XHTML 2.0]] which is in draft stage; now a semantic element in [[HTML5]] --> |
||
:In [[HTML 4]], set font to '''boldface''' where possible. Equivalent CSS: {{code|lang=css|code={font-weight: bold} |
:In [[HTML 4]], set font to '''boldface''' where possible. Equivalent CSS: {{code|lang=css|code={ font-weight: bold; } }}. The {{tag|b|o}} element usually has the same effect in visual browsers, as well as having more semantic meaning, under [[HTML 4.01]]. |
||
:In [[HTML5]], however, {{ |
:In [[HTML5]], however, {{tag|b|o}} has its own meaning, distinct from that of {{tag|strong|o}}. It denotes "text to which attention is being drawn for utilitarian purposes without conveying any extra importance and with no implication of an alternate voice or mood."<ref name="html5-b-element">{{citation|url=http://developers.whatwg.org/text-level-semantics.html#the-b-element |title=4.6 Text-level semantics — The b element |publisher=Developers.whatwg.org |date= |accessdate=2012-03-26}}</ref> |
||
:<code>B</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:<code>B</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
||
{{Anchor|i|i_tag}}{{XMLElement|i|Italic|...}} <!-- not deprecated in HTML 4.01; not included in XHTML 2.0 which is in draft stage; now a semantic element in HTML5 --> |
{{Anchor|i|i_tag}}{{XMLElement|i|Italic|...}} <!-- not deprecated in HTML 4.01; not included in XHTML 2.0 which is in draft stage; now a semantic element in HTML5 --> |
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:In [[HTML 4]], set font to ''italic'' where possible. Equivalent [[CSS]]: {{code|lang=css|code={font-style: italic} |
:In [[HTML 4]], set font to ''italic'' where possible. Equivalent [[CSS]]: {{code|lang=css|code={ font-style: italic; } }}. Using {{tag|em}} has the same visual effect in most browsers, as well as having a semantic meaning as ''emphasis'', under [[HTML 4.01]]. (Purely typographic italics have many non-emphasis purposes, as HTML 5 more explicitly recognized.) |
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:In [[HTML5]], however, {{ |
:In [[HTML5]], however, {{tag|i|o}} has its own semantic meaning, distinct from that of {{tag|em|o}}. It denotes "a different quality of text" or "an alternative voice or mood "e.g., a thought, a ship name, a [[Binomial nomenclature|binary species name]], a foreign-language phrase, etc."<ref name="html5-i-element">{{citation|url=http://developers.whatwg.org/text-level-semantics.html#the-i-element |title=4.6 Text-level semantics — The i element |publisher=Developers.whatwg.org |date= |accessdate=2012-03-26}}</ref> |
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:<code>I</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:<code>I</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
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{{Anchor|u|u_tag}}{{XMLElement|u|Underlined|...}} |
{{Anchor|u|u_tag}}{{XMLElement|u|Underlined|...}} |
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:In [[HTML 4]], <u>underlined</u> text. Equivalent CSS: {{code|lang=css|code={text-decoration: underline} |
:In [[HTML 4]], <u>underlined</u> text. Equivalent CSS: {{code|lang=css|code={ text-decoration: underline; } }}. Deprecated in [[HTML 4.01]]. Restored in [[#HTML5|HTML5]]. |
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:In [[HTML5]], the {{ |
:In [[HTML5]], the {{tag|u|o}} element denotes "a span of text with an unarticulated, though explicitly rendered, non-textual annotation, such as labelling the text as being a proper name in Chinese text (a Chinese proper name mark), or labelling the text as being misspelt." The [[HTML5]] specification reminds developers that other elements are almost always more appropriate than {{tag|u|o}} and admonishes designers not to use underlined text where it could be confused for a hyper-link.<ref name="html5-u-element">{{citation|url=http://developers.whatwg.org/text-level-semantics.html#the-u-element |title=4.6 Text-level semantics — The u element |publisher=Developers.whatwg.org |date= |accessdate=2012-03-26}}</ref> |
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:<code>U</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', was '''standardized''' in [[#HTML32|HTML 3.2]] but was '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]] and was '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. '''Reintroduced''' in [[#HTML5|HTML5]]. |
:<code>U</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', was '''standardized''' in [[#HTML32|HTML 3.2]] but was '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]] and was '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. '''Reintroduced''' in [[#HTML5|HTML5]]. |
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{{Anchor|small|small_tag}}{{XMLElement|small|Small|...}} |
{{Anchor|small|small_tag}}{{XMLElement|small|Small|...}} |
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:In [[HTML 4]], decreased font size (<small>smaller</small> text). Equivalent CSS: {{code|lang=css|code={font-size: smaller} |
:In [[HTML 4]], decreased font size (<small>smaller</small> text). Equivalent CSS: {{code|lang=css|code={ font-size: smaller; } }} |
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:In [[HTML5]], the {{ |
:In [[HTML5]], the {{tag|small|o}} element denotes "side comments such as small print."<ref name="html5-small-element">{{citation|url=http://developers.whatwg.org/text-level-semantics.html#the-small-element |title=4.6 Text-level semantics — The small element |publisher=Developers.whatwg.org |date= |accessdate=2012-03-26}}</ref> This has caused some confusion with the {{tag|[[#aside|aside]]}} element. |
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:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
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{{Anchor|s|s_tag}}{{XMLElement|s|Strikethrough|...}} |
{{Anchor|s|s_tag}}{{XMLElement|s|Strikethrough|...}} |
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:In [[HTML 4]], indicated strike-through text (<s>Strikethrough</s>) and was equivalent to {{ |
:In [[HTML 4]], indicated strike-through text (<s>Strikethrough</s>) and was equivalent to {{tag|strike|o}}. |
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:In [[HTML5]], the {{ |
:In [[HTML5]], the {{tag|s|o}} element denotes information that is "no longer accurate or no longer relevant", and is not to be confused with {{tag|del|o}}, which indicates removal/deletion.<ref name="html5-s-element">{{citation|url=http://developers.whatwg.org/text-level-semantics.html#the-s-element |title=4.6 Text-level semantics — The s element |publisher=Developers.whatwg.org |date= |accessdate=2012-03-26}}</ref> |
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:<code>S</code> was '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]] (having not appeared in any previous standard), and was '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. '''Reintroduced''' in [[#HTML5|HTML5]]. |
:<code>S</code> was '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]] (having not appeared in any previous standard), and was '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. '''Reintroduced''' in [[#HTML5|HTML5]], which instead deprecated {{tag|strike|o}}. |
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{{Anchor|big|big_tag}}{{XMLElement|big|Big|...|deprecated=1}} |
{{Anchor|big|big_tag}}{{XMLElement|big|Big|...|deprecated=1}} |
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:Increased font size (<big>bigger</big> text). Equivalent CSS: {{code|lang=css|code={font-size: larger |
:Increased font size (<big>bigger</big> text). Equivalent CSS: {{code|lang=css|code={ font-size: larger; } }} |
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:'''Standardized''' in [[#HTML32|HTML 3.2]]; '''not supported''' in [[#HTML5|HTML5]]. |
:'''Standardized''' in [[#HTML32|HTML 3.2]]; '''not supported''' in [[#HTML5|HTML5]]. |
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{{Anchor|strike|strike_tag}}{{XMLElement|strike|Strikethrough|...|}} |
{{Anchor|strike|strike_tag}}{{XMLElement|strike|Strikethrough|...|}} |
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:Strike-through text (<s>Strikethrough</s>), (Equivalent CSS: {{code|lang=css|code={text-decoration: line-through} |
:Strike-through text (<s>Strikethrough</s>), (Equivalent CSS: {{code|lang=css|code={ text-decoration: line-through; } }}) |
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:<code>STRIKE</code> was standardized in [[#HTML32|HTML 3.2]]; '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]]; '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. |
:<code>STRIKE</code> was standardized in [[#HTML32|HTML 3.2]]; '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]]; '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. |
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{{Anchor|tt|tt_tag}}{{XMLElement|tt|Teletype|...|deprecated=1}} |
{{Anchor|tt|tt_tag}}{{XMLElement|tt|Teletype|...|deprecated=1}} |
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:[[non-proportional font|Fixed-width]] font ( |
:[[non-proportional font|Fixed-width]] font ({{mono|typewriter-like}}<!-- DO NOT use actual deprecated markup in this page; use CSS to simulate its output.-->), also known as [[teletype]], thus "tt". (Equivalent CSS: {{code|lang=css|code={ font-family: monospace; } }}) |
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:<code>TT</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''Standardized''' in [[#HTML20|HTML 2.0]]; not supported<ref name="html5-tt-not-supported">{{citation|url=http://www.w3.org/TR/html5/obsolete.html#non-conforming-features |title=11 Obsolete features — HTML5 |publisher=W3.org |date= |accessdate=2012-03-26}}</ref> in HTML5. Possible replacements: [[#kbd|{{ |
:<code>TT</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''Standardized''' in [[#HTML20|HTML 2.0]]; not supported<ref name="html5-tt-not-supported">{{citation|url=http://www.w3.org/TR/html5/obsolete.html#non-conforming-features |title=11 Obsolete features — HTML5 |publisher=W3.org |date= |accessdate=2012-03-26}}</ref> in HTML5. Possible replacements: [[#kbd|{{tag|kbd|o}}]] for marking user input, [[#var|{{tag|var|o}}]] for variables (usually rendered italic, and not with a change to monospace), [[#code|{{tag|code|o}}]] for source code, [[#samp|{{tag|samp|o}}]] for output.<ref name="html5-tt-not-supported" /> |
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<!-- font description start --> |
<!-- font description start --> |
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{{Anchor|font|font_tag}}{{XMLElement|font|Teletype|...|}} |
{{Anchor|font|font_tag}}{{XMLElement|font|Teletype|...|}} |
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:Equivalent CSS for font attributes: |
:Equivalent CSS for font attributes: |
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:*<code class="mw-highlight" dir="rtl"><span class="p"><</span><span class="nt">font</span> <span class="na">size</span><span class="o">=</span><span class="s">"<var>N</var>"</span><span class="p">></span></code> corresponds to <code class="mw-highlight" dir="ltr"><span class="p">{</span><span class="nb">font-size</span><span class="o" style="color: #666;">:</span> <span class="nb"><var>Y</var><var>units</var></span><span class="p">}</span></code> (the HTML specification does not define the relationship between size <var>N</var> and unit-size <var>Y</var>, nor does it define a unit). |
:*<code class="mw-highlight" dir="rtl"><span class="p"><</span><span class="nt">font</span> <span class="na">size</span><span class="o">=</span><span class="s">"<var>N</var>"</span><span class="p">></span></code> corresponds to <code class="mw-highlight" dir="ltr"><span class="p">{</span><span class="nb">font-size</span><span class="o" style="color: #666;">:</span> <span class="nb"><var>Y</var><var>units</var></span><span class="p">}</span></code> (the HTML specification does not define the relationship between size <var>N</var> and unit-size <var>Y</var>, nor does it define a unit). |
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:*{{code|lang=html|code=<font color="red">}} corresponds to {{code|lang=css|code={color: red} |
:*{{code|lang=html|code=<font color="red">}} corresponds to {{code|lang=css|code={ color: red; } }} |
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:*{{code|lang=html|code=<font face=" |
:*{{code|lang=html|code=<font face="Times New Roman">}} corresponds to {{code|lang=css|code={ font-family: 'Times New Roman', Times, serif; } }} – CSS supports a [[font stack]], of two or more alternative fonts. |
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:'''Standardized''' in [[#HTML32|HTML 3.2]]; '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]]; '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. Not part of HTML5. |
:'''Standardized''' in [[#HTML32|HTML 3.2]]; '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]]; '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. Not part of HTML5. |
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{{Anchor|cite|cite_tag}}{{XMLElement|cite|Citation|...}} |
{{Anchor|cite|cite_tag}}{{XMLElement|cite|Citation|...}} |
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:A citation or a reference for a quote or statement in the document. |
:A citation or a reference for a quote or statement in the document. |
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: |
:CITE existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
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:''Note:'' The HTML 5 specifications have been confusingly [[Fork (software development)|forked]],<ref name=finalars>{{cite web |url= https://arstechnica.com/information-technology/2014/10/html5-specification-finalized-squabbling-over-who-writes-the-specs-continues/ |title=HTML5 specification finalized, squabbling over specs continues |publisher=Ars Technica |date=29 October 2014 |access-date=29 October 2014}}</ref> including with regard to this element. In HTML 4 and earlier, {{tag|cite|o}} was for "a citation or a reference to other sources" without any particular limitations or requirements.<ref>{{cite web |title=9.2.1 Phrase elements: EM, STRONG, DFN, CODE, SAMP, KBD, VAR, CITE, ABBR, and ACRONYM |work=HTML 4.01 Specification |date=24 December 1999 |publisher=[[W3C]] |url= https://www.w3.org/TR/html401/struct/text.html#h-9.2.1 |access-date=26 July 2018}}</ref> The [[W3C]] HTML 5 spec uses a refinement of this idea, reflecting how the element has historically been used, but now requiring that it contain (but not be limited to) at least one of "the title of the work or the name of the author (person, people or organization) or an URL reference, or a reference in abbreviated form as per the conventions used for the addition of citation metadata."<ref>[[#HTML52|''HTML 5.2 W3C Recommendation'']], at [https://www.w3.org/TR/html52/textlevel-semantics.html#the-cite-element "§ 4.5.6. The cite element"].</ref> But the WHATWG spec only permits the element to be used around the title of a work.<ref>[[#WHATWGLS|''HTML Living Standard'']], at [https://html.spec.whatwg.org/multipage/text-level-semantics.html#the-cite-element "§ 4.5.6 The cite element"].</ref> The W3C specs began with the broader definition, then switched to the very narrow one after WHATWG made this change. However, W3C reverted their own change in 2012, in response to negative developer-community feedback; the element was in broadly-deployed use with the broader scope, e.g., various blog and forum platforms wrap commenters' IDs and e-mail addresses in {{tag|cite}}, and people using the element for bibliographic citations were (and still are) routinely wrapping each entire citation in this element. |
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:Another problem with the element is that WHATWG recommends that it be italicized by default (thus almost all browsers do so), because it (in their view) is only for publication titles. By convention, however, only certain kinds of titles actually take italics, while others are expected to be put in quotation marks, and standards may actually vary by publishing context and language. Consequently, many website authors and admins use a site-wide stylesheet to undo this element's auto-italics. |
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{{Anchor|data|data_tag}}{{XMLElement|data|Data|...}} |
{{Anchor|data|data_tag}}{{XMLElement|data|Data|...}} |
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:Links inline content with a machine-readable translation. |
:Links inline content with a machine-readable translation. |
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:'''Standardized''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/data|title= |
:'''Standardized''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/data|title=<data>|website=MDN Web Docs}}</ref> |
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{{Anchor|del|del_tag}}{{XMLElement|del|Deleted|...}} |
{{Anchor|del|del_tag}}{{XMLElement|del|Deleted|...}} |
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Line 605: | Line 610: | ||
{{Anchor|ins|ins_tag}}{{XMLElement|ins|Inserted|...}} |
{{Anchor|ins|ins_tag}}{{XMLElement|ins|Inserted|...}} |
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:Inserted text. Often used to mark up replacement text for {{ |
:Inserted text. Often used to mark up replacement text for material struck with {{tag|del|o}} or {{tag|s|o}}. Typically rendered [[underline]]d: <ins>Inserted text.</ins> |
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:'''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
:'''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
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:Both {{tag|ins|o}} and {{tag|ins|del|o}} elements may also be used as block elements: containing other block and inline elements. However, these elements must still remain wholly within their parent element to maintain a well-formed HTML document. For example, deleting text from the middle of one paragraph across several other paragraphs and ending in a final paragraph would need to use three separate {{tag|ins|del|o}} elements. Two {{tag|ins|del|o}} elements would be required as inline elements to indicate the deletion of text in the first and last paragraphs, and a third, used as a block element, to indicate the deletion in the intervening paragraphs. |
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::Note, both {{code|lang=html|code=<ins>}} and {{code|lang=html|code=<del>}} elements may also be used as block elements: containing other block and inline elements. However, these elements must still remain wholly within their parent element to maintain a well-formed HTML document. For example, deleting text from the middle of one paragraph across several other paragraphs and ending in a final paragraph would need to use three separate {{code|lang=html|code=<del>}} elements. Two {{code|lang=html|code=<del>}} elements would be required as inline element to indicate the deletion of text in the first and last paragraphs, and a third, used as a block element, to indicate the deletion in the intervening paragraphs. |
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{{Anchor|mark|mark_tag}}{{XMLElement|mark|Mark|...}} |
{{Anchor|mark|mark_tag}}{{XMLElement|mark|Mark|...}} |
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Line 615: | Line 619: | ||
{{Anchor|q|q_tag}}{{XMLElement|q|Quote|...}} |
{{Anchor|q|q_tag}}{{XMLElement|q|Quote|...}} |
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:An inline quotation (for block level quotation see [[#blockquote| |
:An inline quotation (for block level quotation see {{tag|[[#blockquote|blockquote]]|o}}). Quote elements may be nested. |
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:{{ |
:{{tag|q|o}} {{em|should}} automatically generate quotation marks in conjunction with style sheets. Practical concerns due to browser non-compliance may force authors to find workarounds. |
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:The <code>cite</code> attribute gives the source, and must be a fully qualified [[Uniform Resource Identifier|URI]]. |
:The <code>cite</code> attribute gives the source, and must be a fully qualified [[Uniform Resource Identifier|URI]]. |
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:'''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
:'''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
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:{{strong|Note:}} Lengthy inline quotations may be displayed as indented blocks (as <code>block-quote</code>) using style sheets. For example, with a suitable CSS rule associated with <code>q.lengthy</code>: {{tag|q |attr=class="lengthy" |content=Lengthy quote here.}} |
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:::{{code|lang=html|code=<q class="lengthy">}}An inline quotation of significant length (e.g., 25 words) goes here.{{code|lang=html|code=</q>}} |
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{{Anchor|rb|rb_tag}}{{XMLElement|rb|Ruby Annotation Base|...|}} |
{{Anchor|rb|rb_tag}}{{XMLElement|rb|Ruby Annotation Base|...|}} |
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Line 628: | Line 631: | ||
{{Anchor|rp|rp_tag}}{{XMLElement|rp|Ruby Fallback Parenthesis|...|}} |
{{Anchor|rp|rp_tag}}{{XMLElement|rp|Ruby Fallback Parenthesis|...|}} |
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:Provides fallback parenthesis for browsers lacking [[Ruby character|ruby annotation]] support. |
:Provides fallback parenthesis for browsers lacking [[Ruby character|ruby annotation]] support. |
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:'''Standardized''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/rp|title= |
:'''Standardized''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/rp|title=<rp>: The Ruby Fallback Parenthesis element|website=MDN Web Docs}}</ref> |
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{{Anchor|rt|rt_tag}}{{XMLElement|rt|Ruby Annotation Pronunciation|...|}} |
{{Anchor|rt|rt_tag}}{{XMLElement|rt|Ruby Annotation Pronunciation|...|}} |
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:Indicates pronunciation for a character in a [[Ruby character|ruby annotation]]. |
:Indicates pronunciation for a character in a [[Ruby character|ruby annotation]]. |
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:'''Standardized''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/rt|title= |
:'''Standardized''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/rt|title=<rt>: The Ruby Text element|website=MDN Web Docs}}</ref> |
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{{Anchor|rtc|rtc_tag}}{{XMLElement|rtc|Ruby Semantic Annotation|...|}} |
{{Anchor|rtc|rtc_tag}}{{XMLElement|rtc|Ruby Semantic Annotation|...|}} |
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:Semantic annotations for a [[Ruby character|ruby annotation]]. |
:Semantic annotations for a [[Ruby character|ruby annotation]]. |
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:'''Standardized''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/rtc|title= |
:'''Standardized''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/rtc|title=<rtc>: The Ruby Text Container element|website=MDN Web Docs}}</ref> |
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{{Anchor|ruby|ruby_tag}}{{XMLElement|ruby|Ruby Annotation|...|}} |
{{Anchor|ruby|ruby_tag}}{{XMLElement|ruby|Ruby Annotation|...|}} |
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:Represents a [[Ruby character|ruby annotation]] for showing the pronunciation of East Asian characters. |
:Represents a [[Ruby character|ruby annotation]] for showing the pronunciation of East Asian characters. |
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:'''Standardized''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/ruby|title= |
:'''Standardized''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/ruby|title=<ruby>|website=MDN Web Docs}}</ref> |
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{{Anchor|script|script_tag}}{{XMLElement|script|Script|...}} |
{{Anchor|script|script_tag}}{{XMLElement|script|Script|...}} |
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:Places a [[scripting language|script]] in the document. Also usable in the head and in block contexts. |
:Places a [[scripting language|script]] in the document. Also usable in the head and in block contexts. |
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::{{ |
::{{em|Note:}} {{tag|script|o}} is not itself either a block or inline element; by itself it should not display at all, but it can contain instructions to dynamically generate either both block or inline content. |
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:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
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{{Anchor|sub|sub_tag}}{{XMLElement|sub|Subscript|...}} and {{Anchor|sup|sup_tag}}{{XMLElement|sup|Superscript|...}} |
{{Anchor|sub|sub_tag}}{{XMLElement|sub|Subscript|...}} and {{Anchor|sup|sup_tag}}{{XMLElement|sup|Superscript|...}} |
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:Mark <sub>[[subscript]]</sub> or <sup>[[superscript]]</sup> text. (Equivalent CSS: {{code|lang=css|code={vertical-align: sub} |
:Mark <sub>[[subscript]]</sub> or <sup>[[superscript]]</sup> text. (Equivalent CSS: {{code|lang=css|code={ vertical-align: sub; } }} and {{code|lang=css|code={ vertical-align: super; } }}, respectively.) |
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:Both were proposed in the [[#HTML30|HTML 3.0 Drafts]]; '''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
:Both were proposed in the [[#HTML30|HTML 3.0 Drafts]]; '''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
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Line 657: | Line 660: | ||
{{Anchor|time|time_tag}}{{XMLElement|time|Time|...|}} |
{{Anchor|time|time_tag}}{{XMLElement|time|Time|...|}} |
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:Represents a time on the 24-hour clock or a date on the [[Gregorian calendar]], optionally with time and timezone information. Also allows times and dates to be represented in a machine-readable format. |
:Represents a time on the 24-hour clock or a date on the [[Gregorian calendar]], optionally with time and timezone information. Also allows times and dates to be represented in a machine-readable format. |
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:'''Standardized''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/time|title= |
:'''Standardized''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/time|title=<time>|website=MDN Web Docs}}</ref> |
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{{Anchor|wbr|wbr_tag}}{{XMLElement|wbr|Word Break Opportunity|...|end=no}} |
{{Anchor|wbr|wbr_tag}}{{XMLElement|wbr|Word Break Opportunity|...|end=no}} |
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Line 666: | Line 669: | ||
{{Anchor|applet|applet_tag}}{{XMLElement|applet|Java Applet|...|deprecated=xhtml}} |
{{Anchor|applet|applet_tag}}{{XMLElement|applet|Java Applet|...|deprecated=xhtml}} |
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:Embeds a [[Java applet]] in the page. Deprecated in favor of {{ |
:Embeds a [[Java applet]] in the page. Deprecated in favor of {{tag|object|o}}, as it could only be used with Java applets, and had accessibility limitations. |
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:'''Standardized''' in [[#HTML32|HTML 3.2]]; '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]]; '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. As of 2011, still widely used as the implementations of the replacing {{ |
:'''Standardized''' in [[#HTML32|HTML 3.2]]; '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]]; '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. As of 2011, still widely used as the implementations of the replacing {{tag|object|o}} are not consistent between different browsers. |
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{{Anchor|area|area_tag}}{{XMLElement|area|Area|...|end=no}} |
{{Anchor|area|area_tag}}{{XMLElement|area|Area|...|end=no}} |
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:Specifies a [[Focus (computing)|focusable]] area in a {{ |
:Specifies a [[Focus (computing)|focusable]] area in a {{tag|map|o}}. |
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:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
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Line 681: | Line 684: | ||
:'''Standardized''' in [[#HTML5|HTML5]]. |
:'''Standardized''' in [[#HTML5|HTML5]]. |
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{{Anchor|embed}}{{XMLElement|embed|Embed|...|}} |
|||
:Inserts a non-standard object (like applet) or external content (typically non-HTML) into the document. Deprecated in HTML 4 in favor of {{ |
:Inserts a non-standard object (like applet) or external content (typically non-HTML) into the document. Deprecated in HTML 4 in favor of {{tag|object|o}}, but then was added back into the HTML5 specification<ref>[http://webdesign.about.com/od/htmltags/p/bltags_embed.htm Jennifer Kyrnin ] {{tag|embed|o}}</ref><ref>[https://www.w3schools.com/tags/tag_embed.asp W3Schools] about {{tag|embed|o}}</ref> |
||
{{Anchor|img|img_tag}}{{XMLElement|img|Image|...|end=no}} |
{{Anchor|img|img_tag}}{{XMLElement|img|Image|...|end=no}} |
||
:Used by visual user agents to insert an [[image]] in the document. The <code>src</code> attribute specifies the image URL. The required [[Alt attribute|<code>alt</code> attribute]] provides alternative text in case the image cannot be displayed.<ref>The alt attribute's text cannot be styled with markup; as a result, other methods of alternative text presentation, such as [[Fahrner Image Replacement]], have been devised to accommodate situations in which the coder wishes styled text to be displayed if images are disabled in a user's browser.</ref> (Though <code>alt</code> is intended as alternative text, Microsoft [[Internet Explorer]] 7 and below render it as a [[tooltip]] if no |
:Used by visual user agents to insert an [[image]] in the document. The <code>src</code> attribute specifies the image URL. The required [[Alt attribute|<code>alt</code> attribute]] provides alternative text in case the image cannot be displayed.<ref>The alt attribute's text cannot be styled with markup; as a result, other methods of alternative text presentation, such as [[Fahrner Image Replacement]], have been devised to accommodate situations in which the coder wishes styled text to be displayed if images are disabled in a user's browser.</ref> (Though <code>alt</code> is intended as alternative text, Microsoft [[Internet Explorer]] 7 and below render it as a [[tooltip]] if no <code>title</code> attribute is given.<ref>{{cite web | url=http://msdn.microsoft.com/en-us/library/cc288472.aspx#access | title=What's New in Internet Explorer 8 – Accessibility and ARIA | publisher=Microsoft | work=MSDN | accessdate=2009-07-22}}</ref> [[Safari (web browser)|Safari]] and [[Google Chrome]], on the other hand, do not display the alt attribute at all.)<ref>{{citation|url=https://bugs.webkit.org/show_bug.cgi?id=5566 |title=Bug 5566 – ALT attribute value sometimes not displayed when image is missing |publisher=Bugs.webkit.org |date= |accessdate=2012-03-26}}</ref> The {{tag|img|s}} element was first proposed by [[Marc Andreessen]] and implemented in the [[Mosaic (web browser)|NSCA Mosaic]] web browser.<ref>{{citation|url=http://1997.webhistory.org/www.lists/www-talk.1993q1/0182.html |title=WWW-Talk Jan-Mar 1993: proposed new tag: IMG |publisher=1997.webhistory.org |date= |accessdate=2012-03-26}}</ref> |
||
:<code>IMG</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:<code>IMG</code> existed in ''[[#HTMLDRAFT12|HTML Internet Draft 1.2]]'', and was '''standardized''' in [[#HTML20|HTML 2.0]]; still current. |
||
Line 697: | Line 700: | ||
{{Anchor|param|param_tag}}{{XMLElement|param|Object Parameter|...|end=no}} |
{{Anchor|param|param_tag}}{{XMLElement|param|Object Parameter|...|end=no}} |
||
:Originally introduced with {{ |
:Originally introduced with {{{tag|applet|o}}}}, this element is now used with, and should only occur as a child of {{tag|object|o}}. It uses [[HTML attributes]] to set a parameter for the object, e.g. width, height, font, background color, etc., depending on the type of object. An object can have multiple {{tag|param|s}} elements. |
||
:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
:'''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
||
{{anchor|source|source_tag}}{{XMLElement|source|Source|...}} |
{{anchor|source|source_tag}}{{XMLElement|source|Source|...}} |
||
:Specifies different sources for audio or video. Makes use of the <code>src</code> attribute in a way similar to the {{ |
:Specifies different sources for audio or video. Makes use of the <code>src</code> attribute in a way similar to the {{tag|video|o}} and {{tag|audio|o}} elements. |
||
:'''Standardized''' in [[#HTML5|HTML5]]. |
:'''Standardized''' in [[#HTML5|HTML5]]. |
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Line 720: | Line 723: | ||
{{Anchor|form|form_tag}}{{XMLElement|form|Form|...|atr={{XMLAttribute|action|Action|url|type=URL|need=required}}}} |
{{Anchor|form|form_tag}}{{XMLElement|form|Form|...|atr={{XMLAttribute|action|Action|url|type=URL|need=required}}}} |
||
:Creates a [[form (web)|form]]. The {{ |
:Creates a [[form (web)|form]]. The {{tag|form|o}} element specifies and operates the overall action of a form area, using the required <code>action</code> attribute. |
||
:'''Standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:'''Standardized''' in [[#HTML20|HTML 2.0]]; still current. |
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Line 732: | Line 735: | ||
{{Anchor|fieldset|fieldset_tag}}{{XMLElement|fieldset|Fieldset|...}} |
{{Anchor|fieldset|fieldset_tag}}{{XMLElement|fieldset|Fieldset|...}} |
||
:A container for adding structure to forms. For example, a series of related controls can be grouped within a {{ |
:A container for adding structure to forms. For example, a series of related controls can be grouped within a {{tag|fieldset|o}}, which can then have a {{tag|legend|o}} added in order to identify their function. |
||
:'''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
:'''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
||
{{Anchor|input|input_tag}}{{XMLElement|input|Input|...|end=no}} |
{{Anchor|input|input_tag}}{{XMLElement|input|Input|...|end=no}} |
||
:{{ |
:{{tag|input|o}} elements allow a variety of standard form controls to be implemented. |
||
:'''Standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:'''Standardized''' in [[#HTML20|HTML 2.0]]; still current. |
||
Line 747: | Line 750: | ||
:{{XMLAttribute|type|Field Type|button|type=ENUM|need=implied}} |
:{{XMLAttribute|type|Field Type|button|type=ENUM|need=implied}} |
||
::A general-purpose button. The element {{ |
::A general-purpose button. The element {{tag|button|o}} is preferred if possible (i.e., if the client supports it) as it provides richer possibilities. |
||
:{{XMLAttribute|type|Field Type|submit|type=ENUM|need=implied}} |
:{{XMLAttribute|type|Field Type|submit|type=ENUM|need=implied}} |
||
Line 798: | Line 801: | ||
{{Anchor|isindex|isindex_tag}}{{XMLElement|isindex|Index|...|end=no|deprecated=1}} |
{{Anchor|isindex|isindex_tag}}{{XMLElement|isindex|Index|...|end=no|deprecated=1}} |
||
:{{ |
:{{tag|isindex|s}} could either appear in the document head or in the body, but only once in a document. |
||
:{{ |
:{{tag|isindex|s}} operated as a primitive HTML search form; but was {{lang|la|[[de facto]]}} obsoleted by more advanced HTML forms introduced in the early to mid-1990s. Represents a set of hyperlinks composed of a base URI, an [[ampersand]] and [[Percent-encoding|percent-encoded]] keywords separated by [[plus sign]]s. |
||
:<code>ISINDEX</code> existed in ''[[#HTMLTAGS|HTML Tags]]''; '''standardized''' in [[#HTML20|HTML 2.0]]; '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]]; '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. |
:<code>ISINDEX</code> existed in ''[[#HTMLTAGS|HTML Tags]]''; '''standardized''' in [[#HTML20|HTML 2.0]]; '''deprecated''' in [[#HTML401|HTML 4.0 Transitional]]; '''invalid''' in [[#HTML401|HTML 4.0 Strict]]. |
||
Line 811: | Line 814: | ||
{{Anchor|legend|legend_tag}}{{XMLElement|legend|Legend|...}} |
{{Anchor|legend|legend_tag}}{{XMLElement|legend|Legend|...}} |
||
:A legend (caption) for a {{ |
:A legend (caption) for a {{tag|fieldset|o}}. |
||
:'''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
:'''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
||
Line 819: | Line 822: | ||
{{Anchor|option|option_tag}}{{XMLElement|option|Select List Option|...|atr={{XMLAttribute|value|Value|x|type=ANY|need=required}}}} |
{{Anchor|option|option_tag}}{{XMLElement|option|Select List Option|...|atr={{XMLAttribute|value|Value|x|type=ANY|need=required}}}} |
||
:Creates an item in a {{ |
:Creates an item in a {{tag|select|o}} list. |
||
:'''Standardized''' in [[#HTML20|HTML 2.0]]; still current. |
:'''Standardized''' in [[#HTML20|HTML 2.0]]; still current. |
||
{{Anchor|optgroup|optgroup_tag}}{{XMLElement|optgroup|Options Group|...|}} |
{{Anchor|optgroup|optgroup_tag}}{{XMLElement|optgroup|Options Group|...|}} |
||
:Identifies a group of {{ |
:Identifies a group of {{tag|option|o}} elements in a {{tag|select|o}} list. |
||
:'''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
:'''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
||
Line 845: | Line 848: | ||
The format of HTML Tables was proposed in the [[#HTML30|HTML 3.0 Drafts]] and the later RFC 1942 ''[[#HTMLTABLES|HTML Tables]]''. They were inspired by the [[CALS Table Model]]. Some elements in these proposals were included in HTML 3.2; the present form of HTML Tables was standardized in HTML 4. (Many of the elements used within tables are neither ''block'' nor ''inline'' elements.) |
The format of HTML Tables was proposed in the [[#HTML30|HTML 3.0 Drafts]] and the later RFC 1942 ''[[#HTMLTABLES|HTML Tables]]''. They were inspired by the [[CALS Table Model]]. Some elements in these proposals were included in HTML 3.2; the present form of HTML Tables was standardized in HTML 4. (Many of the elements used within tables are neither ''block'' nor ''inline'' elements.) |
||
{{Anchor|table|table_tag}}{{XMLElement|table|Table|...|}} |
|||
:Identifies a table. Several [[HTML attributes]] are possible in HTML Transitional, but most of these are invalid in HTML Strict and can be replaced with style sheets. The <code>summary</code> attribute is informally required for accessibility purposes, though its usage is not simple. |
:Identifies a table. Several [[HTML attributes]] are possible in HTML Transitional, but most of these are invalid in HTML Strict and can be replaced with style sheets. The <code>summary</code> attribute is informally required for accessibility purposes, though its usage is not simple. |
||
:Proposed in the [[#HTML30|HTML 3.0 Drafts]]; '''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
:Proposed in the [[#HTML30|HTML 3.0 Drafts]]; '''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
||
{{Anchor|tr|tr_tag}}{{XMLElement|tr|Table Row|...|}} |
|||
:Contains a row of cells in a {{ |
:Contains a row of cells in a {{tag|table|o}}. |
||
:Proposed in the [[#HTML30|HTML 3.0 Drafts]]; '''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
:Proposed in the [[#HTML30|HTML 3.0 Drafts]]; '''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
||
{{Anchor|th|th_tag}}{{XMLElement|th|Table Header Cell|...|}} |
|||
:A {{ |
:A {{tag|table|o}} header cell; contents are conventionally displayed bold and centered. An [[aural]] user agent may use a louder voice for these items. |
||
:Proposed in the [[#HTML30|HTML 3.0 Drafts]]; '''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
:Proposed in the [[#HTML30|HTML 3.0 Drafts]]; '''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
||
{{Anchor|td|td_tag}}{{XMLElement|td|Table Data Cell|...|}} |
|||
:A {{ |
:A {{tag|table|o}} data cell. |
||
:Proposed in the [[#HTML30|HTML 3.0 Drafts]]; '''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
:Proposed in the [[#HTML30|HTML 3.0 Drafts]]; '''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
||
{{Anchor|colgroup|colgroup_tag}}{{XMLElement|colgroup|Column Group|...|}} |
|||
:Specifies a column group in a {{ |
:Specifies a column group in a {{tag|table|o}}. |
||
:Proposed in [[#HTMLTABLES|HTML Tables]]; '''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
:Proposed in [[#HTMLTABLES|HTML Tables]]; '''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
||
{{Anchor|col|col_tag}}{{XMLElement|col|Table Column|...|}} |
|||
:Specifies a column in a {{ |
:Specifies a column in a {{tag|table|o}}. |
||
:Proposed in [[#HTMLTABLES|HTML Tables]]; '''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
:Proposed in [[#HTMLTABLES|HTML Tables]]; '''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
||
{{Anchor|caption|caption_tag}}{{XMLElement|caption|Table Caption|...|}} |
|||
:Specifies a caption for a {{ |
:Specifies a caption for a {{tag|table|o}}. |
||
:Proposed in the [[#HTML30|HTML 3.0 Drafts]]; '''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
:Proposed in the [[#HTML30|HTML 3.0 Drafts]]; '''Standardized''' in [[#HTML32|HTML 3.2]]; still current. |
||
{{Anchor|thead|thead_tag}}{{XMLElement|thead|Table Header|...|}} |
|||
:Specifies the header part of a {{ |
:Specifies the header part of a {{tag|table|o}}. This section may be repeated by the user agent if the table is split across pages (in printing or other paged media). |
||
:Proposed in [[#HTMLTABLES|HTML Tables]]; '''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
:Proposed in [[#HTMLTABLES|HTML Tables]]; '''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
||
{{Anchor|tbody|tbody_tag}}{{XMLElement|tbody|Table Body|...|}} |
|||
:Specifies a body of data for a {{ |
:Specifies a body of data for a {{tag|table|o}}. |
||
:Proposed in [[#HTMLTABLES|HTML Tables]]; '''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
:Proposed in [[#HTMLTABLES|HTML Tables]]; '''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
||
{{Anchor|tfoot|tfoot_tag}}{{XMLElement|tfoot|Table Footer|...|}} |
|||
:Specifies the footer part of a {{ |
:Specifies the footer part of a {{tag|table|o}}. Like {{tag|thead|o}}, this section may be repeated by the user agent if the table is split across pages (in printing or other paged media). |
||
:Proposed in [[#HTMLTABLES|HTML Tables]]; '''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
:Proposed in [[#HTMLTABLES|HTML Tables]]; '''Standardized''' in [[#HTML401|HTML 4.0]]; still current. |
||
Line 879: | Line 882: | ||
{{Main|Framing (World Wide Web)}} |
{{Main|Framing (World Wide Web)}} |
||
Frames allow a visual HTML Browser window to be split into segments, each of which can show a different document. This can lower bandwidth use, as repeating parts of a layout can be used in one frame, while variable content is displayed in another. This may come at a certain usability cost, especially in non-visual user agents,<ref>{{cite web|url=http://www.washington.edu/doit/are-frames-accessible|title=Are frames accessible?|quote=...frames do present additional usability challenges that are unique to users with disabilities, particularly those who use screen readers.}}</ref> due to separate and independent documents (or websites) being displayed adjacent to each other and being allowed to interact with the same parent window. Because of this cost, frames (excluding the {{ |
Frames allow a visual HTML Browser window to be split into segments, each of which can show a different document. This can lower bandwidth use, as repeating parts of a layout can be used in one frame, while variable content is displayed in another. This may come at a certain usability cost, especially in non-visual user agents,<ref>{{cite web|url=http://www.washington.edu/doit/are-frames-accessible|title=Are frames accessible?|quote=...frames do present additional usability challenges that are unique to users with disabilities, particularly those who use screen readers.}}</ref> due to separate and independent documents (or websites) being displayed adjacent to each other and being allowed to interact with the same parent window. Because of this cost, frames (excluding the {{tag|iframe|o}} element) are only allowed in HTML 4.01 Frame-set. Iframes can also hold documents on different servers. In this case the interaction between windows is blocked by the browser. Sites like [[Facebook]] and [[Twitter]] use iframes to display content (plugins) on third party websites. Google [[AdSense]] uses iframes to display banners on third party websites. |
||
In HTML 4.01, a document may contain a {{ |
In HTML 4.01, a document may contain a {{tag|head|o}} and a {{tag|body|o}}} {{em|or}} a {{tag|head|o}} and a {{tag|frameset|o}}, but not both a {{tag|body|o}} and a {{tag|frameset|o}}. However, {{tag|iframe|o}} can be used in a normal document body. |
||
{{Anchor|frameset|frameset_tag}}{{XMLElement|frameset|Frameset|...|deprecated=1}} |
|||
:Contains the set of {{ |
:Contains the set of {{tag|frame|s}} elements for a document. The layout of frames is given by comma separated lists in the <code>rows</code> and <code>cols</code> [[HTML attributes]]. |
||
:'''Standardized''' in [[#HTML401|HTML 4.0]] Frameset, '''obsolete''' in HTML5. |
:'''Standardized''' in [[#HTML401|HTML 4.0]] Frameset, '''obsolete''' in HTML5. |
||
{{Anchor|frame|frame_tag}}{{XMLElement|frame|Frame|...|end=no|deprecated=1}} |
|||
:Defines a single frame, or region, within the {{ |
:Defines a single frame, or region, within the {{tag|frameset|o}}. A separate document is linked to a frame using the <code>src</code> attribute inside the {{tag|frame|s}} element. |
||
:'''Standardized''' in [[#HTML401|HTML 4.0]] Frameset, '''obsolete''' in HTML5. |
:'''Standardized''' in [[#HTML401|HTML 4.0]] Frameset, '''obsolete''' in HTML5. |
||
{{Anchor|noframes|noframes_tag}}{{XMLElement|noframes|Frame Support Fallback|...|deprecated=1}} |
|||
:Contains normal HTML content for user agents that don't support {{ |
:Contains normal HTML content for user agents that don't support {{tag|frame|s}} elements. |
||
:'''Standardized''' in [[#HTML401|HTML 4.0]] Transitional, '''obsolete''' in HTML5. |
:'''Standardized''' in [[#HTML401|HTML 4.0]] Transitional, '''obsolete''' in HTML5. |
||
{{Anchor|iframe|iframe_tag}}{{XMLElement|iframe|Inline Frame|...|}} |
|||
:An inline frame places another HTML document in a frame. Unlike an {{ |
:An inline frame places another HTML document in a frame. Unlike an {{tag|object|s}} element, an {{tag|iframe|o}} can be the "target" frame for links defined by other elements, and it can be selected by the user agent as the focus for printing, viewing its source, and so on. |
||
:The content of the element is used as alternative text to be displayed if the browser does not support inline frames. |
:The content of the element is used as alternative text to be displayed if the browser does not support inline frames. |
||
:First introduced by Microsoft Internet Explorer in 1997, '''standardized''' in [[#HTML401|HTML 4.0]] Transitional, '''allowed''' in HTML5. |
:First introduced by Microsoft Internet Explorer in 1997, '''standardized''' in [[#HTML401|HTML 4.0]] Transitional, '''allowed''' in HTML5. |
||
===<code>longdesc</code> attribute=== |
===<code>longdesc</code> attribute=== |
||
In [[HTML]], '''<code>longdesc</code>''' is an attribute used within the {{ |
In [[HTML]], '''<code>longdesc</code>''' is an attribute used within the {{tag|img|s}}, {{tag|frame|s}}, or {{tag|iframe|o}} elements. It is supposed to be a [[URL]]{{refn|group=note|Strictly an [[Internationalized resource identifier|IRI]], not a URL; although URLs are a subset of IRIs.}} to a document that provides a '''long description''' for the image, frame, or iframe in question.<ref>{{cite web|url=http://www.w3.org/TR/REC-html40/struct/objects.html|title=Objects, Images, and Applets|publisher=W3C|accessdate=2008-12-20}}</ref> Note that this attribute should contain a URL, and {{em|not}} – as is commonly mistaken – the text of the description itself. |
||
<code>longdesc</code> was designed to be used by [[screen reader]]s to display image information for computer users with [[accessibility]] issues, such as the blind or visually impaired, and is widely implemented by both web browsers and screen readers.<ref>{{cite web|url=http://www.w3.org/html/wg/wiki/ChangeProposals/InstateLongdesc/Implementation|title=InState Longdesc|accessdate=2011-09-05}}</ref> Some developers object that |
<code>longdesc</code> was designed to be used by [[screen reader]]s to display image information for computer users with [[accessibility]] issues, such as the blind or visually impaired, and is widely implemented by both web browsers and screen readers.<ref>{{cite web|url=http://www.w3.org/html/wg/wiki/ChangeProposals/InstateLongdesc/Implementation|title=InState Longdesc|accessdate=2011-09-05}}</ref> Some developers object that |
||
Line 916: | Line 919: | ||
====Linking to the long description in the text==== |
====Linking to the long description in the text==== |
||
Since very few graphical browsers support making the link available natively (Opera and iCab being the exceptions), it is useful to include a link to the description page near the {{ |
Since very few graphical browsers support making the link available natively (Opera and iCab being the exceptions), it is useful to include a link to the description page near the {{tag|img|s}} element whenever possible, as this can also aid sighted users. |
||
=====Example===== |
=====Example===== |
||
Line 928: | Line 931: | ||
The following elements were part of the early HTML developed by [[Tim Berners-Lee]] from 1989–91; they are mentioned in ''HTML Tags'', but deprecated in ''HTML 2.0'' and were never part of HTML standards. |
The following elements were part of the early HTML developed by [[Tim Berners-Lee]] from 1989–91; they are mentioned in ''HTML Tags'', but deprecated in ''HTML 2.0'' and were never part of HTML standards. |
||
{{Anchor|listing|listing_tag}}{{XMLElement|listing|HTML Listing|...|deprecated=1}} |
|||
:This element displayed the text inside the tags in a monospace font and without interpreting the HTML. The [[#HTML20|HTML 2.0]] specification recommended rendering the element at up to 132 characters per line. |
:This element displayed the text inside the tags in a monospace font and without interpreting the HTML. The [[#HTML20|HTML 2.0]] specification recommended rendering the element at up to 132 characters per line. |
||
:'''Deprecated''' in [[#HTML32|HTML 3.2]]; '''obsolete''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/listing|title= |
:'''Deprecated''' in [[#HTML32|HTML 3.2]]; '''obsolete''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/listing|title=<listing>|website=MDN Web Docs}}</ref> |
||
{{Anchor|plaintext|plaintext_tag}}{{XMLElement|plaintext|Plaintext|...|deprecated=1|end=no}} |
|||
:{{ |
:{{tag|plaintext|s}} does not have an end tag as it terminates the markup and causes the rest of the document to be parsed as if it were [[plaintext]]. |
||
:{{ |
:{{tag|plaintext|s}} existed in ''[[#HTMLTAGS|HTML Tags]]''; '''deprecated''' in [[#HTML20|HTML 2.0]]; '''invalid''' in [[#HTML401|HTML 4.0]]. |
||
{{Anchor|xmp|xmp_tag}}{{XMLElement|xmp|HTML Example|...|deprecated=1}} |
|||
:This element displayed the text inside the tags in a monospace font and without interpreting the HTML. The [[#HTML20|HTML 2.0]] specification recommended rendering the element at 80 characters per line. |
:This element displayed the text inside the tags in a monospace font and without interpreting the HTML. The [[#HTML20|HTML 2.0]] specification recommended rendering the element at 80 characters per line. |
||
:'''Deprecated''' in [[#HTML32|HTML 3.2]]; '''obsolete''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/xmp|title= |
:'''Deprecated''' in [[#HTML32|HTML 3.2]]; '''obsolete''' in [[#HTML5|HTML5]].<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/xmp|title=<xmp>|website=MDN Web Docs}}</ref> |
||
{{Anchor|nextid|nextid_tag}}{{XMLElement|nextid|NeXT ID|...|deprecated=1|end=no}} |
|||
:This element enabled NeXT web designing tool to generate automatic NAME labels for its anchors and was itself automatically generated.<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/nextid|title= |
:This element enabled NeXT web designing tool to generate automatic NAME labels for its anchors and was itself automatically generated.<ref>{{cite web|url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/nextid|title=<nextid>: The NeXT ID element (Obsolete)|website=MDN Web Docs}}</ref> |
||
:{{ |
:{{tag|nextid|s}} existed in ''[[#HTMLTAGS|HTML Tags]]'' (described as obsolete); '''deprecated''' in [[#HTML20|HTML 2.0]]; '''invalid''' in [[#HTML32|HTML 3.2]] and later. |
||
==Non-standard elements== |
==Non-standard elements== |
||
{{Main|Comparison of layout engines (Non-standard HTML)}} |
{{Main|Comparison of layout engines (Non-standard HTML)}} |
||
This section lists some widely used obsolete elements, which means they are not used in [[Validator|valid]] code. They may not be supported in all user agents. |
This section lists some widely used obsolete elements, which means they are not used in [[Validator|valid]] code. They may not be supported in all user agents. |
||
;{{Anchor|blink}}{{XMLElement|blink|Blink|...|deprecated=1}} |
|||
{{Anchor|blink}}{{XMLElement|blink|Blink|...|deprecated=1}} |
|||
:Causes text to blink. Introduced in imitation of the [[ANSI escape code]]s. Can be done with CSS where supported: {{code|lang=css|code={text-decoration: blink}<nowiki />}} (This effect may have negative consequences for people with [[photosensitive epilepsy]];<ref name="WCAG">{{cite web|url=http://www.w3.org/TR/WCAG10/|title=Web Content Accessibility Guidelines 1.0|first1=Wendy|last1=Chisholm|first2=Gregg|last2=Vanderheiden|first3=Ian|last3=Jacobs|publisher=World Wide Web Consortium|date=1999-05-05|accessdate=2010-07-20}}</ref> its use on the public Internet should follow the appropriate guidelines.) |
:Causes text to blink. Introduced in imitation of the [[ANSI escape code]]s. Can be done with CSS where supported: {{code|lang=css|code={text-decoration: blink}<nowiki />}} (This effect may have negative consequences for people with [[photosensitive epilepsy]];<ref name="WCAG">{{cite web|url=http://www.w3.org/TR/WCAG10/|title=Web Content Accessibility Guidelines 1.0|first1=Wendy|last1=Chisholm|first2=Gregg|last2=Vanderheiden|first3=Ian|last3=Jacobs|publisher=World Wide Web Consortium|date=1999-05-05|accessdate=2010-07-20}}</ref> its use on the public Internet should follow the appropriate guidelines.) |
||
:{{code|lang=html|code=<blink>}} originated in [[Netscape Navigator]] and is mostly recognized by its descendants, including [[Firefox]]; '''deprecated''' or '''invalid''' in [[#HTML20|HTML 2.0]] and later. Note that the replacement CSS tag, while standard, is not required to be supported. |
:{{code|lang=html|code=<blink>}} originated in [[Netscape Navigator]] and is mostly recognized by its descendants, including [[Firefox]]; '''deprecated''' or '''invalid''' in [[#HTML20|HTML 2.0]] and later. Note that the replacement CSS tag, while standard, is not required to be supported. |
||
{{Anchor|marquee}}{{XMLElement|marquee|Marquee|...|deprecated=1}} |
|||
:Creates scrolling text. Can be done with scripting instead. (This effect may have negative consequences for people with [[photosensitive epilepsy]];<ref name="WCAG" /> its use on the public Internet should follow the appropriate guidelines.) There are three options, including '''Alternate''', '''Scroll''' and '''slide'''. '''Scrolldelay''' can also be added. |
:Creates scrolling text. Can be done with scripting instead. (This effect may have negative consequences for people with [[photosensitive epilepsy]];<ref name="WCAG" /> its use on the public Internet should follow the appropriate guidelines.) There are three options, including '''Alternate''', '''Scroll''' and '''slide'''. '''Scrolldelay''' can also be added. |
||
:{{code|lang=html|code=<marquee>}} originated in [[Microsoft Internet Explorer]]; '''deprecated''' or '''invalid''' in [[#HTML20|HTML 4.01]] and later. |
:{{code|lang=html|code=<marquee>}} originated in [[Microsoft Internet Explorer]]; '''deprecated''' or '''invalid''' in [[#HTML20|HTML 4.01]] and later. |
||
{{Anchor|nobr}}{{XMLElement|nobr|No Break|...|deprecated=1}} |
|||
:Causes text to not break at end of line, preventing word wrap where text exceeds the width of the enclosing object. Adjacent text may break before and after it. Can be done with CSS: {{code|lang=css|code={white-space: nowrap;}<nowiki />}} |
:Causes text to not break at end of line, preventing word wrap where text exceeds the width of the enclosing object. Adjacent text may break before and after it. Can be done with CSS: {{code|lang=css|code={white-space: nowrap;}<nowiki />}} |
||
:{{code|lang=html|code=<nobr>}} is a proprietary element which is recognized by most browsers for compatibility reasons; '''deprecated''' or '''invalid''' in [[#HTML20|HTML 2.0]] and later. |
:{{code|lang=html|code=<nobr>}} is a proprietary element which is recognized by most browsers for compatibility reasons; '''deprecated''' or '''invalid''' in [[#HTML20|HTML 2.0]] and later. |
||
{{Anchor|noembed}}{{XMLElement|noembed|Embed Fallback|...|deprecated=1}} |
|||
:Specifies alternative content, if the embed cannot be rendered. Replaced by the content of the {{code|lang=html|code=<embed>}} or {{code|lang=html|code=<object>}} element. |
:Specifies alternative content, if the embed cannot be rendered. Replaced by the content of the {{code|lang=html|code=<embed>}} or {{code|lang=html|code=<object>}} element. |
||
Line 964: | Line 968: | ||
Unlike most HTML tags, comments do not nest. |
Unlike most HTML tags, comments do not nest. |
||
The markup {{code|lang=html|code=<!<nowiki />--Xbegin<<nowiki />!--Y-->Xend-->}} will yield the comment |
The markup {{code|lang=html|code=<!<nowiki />--Xbegin<<nowiki />!--Y-->Xend-->}} will yield the comment {{samp|{{nobr|Xbegin<!--Y}}}} and the text {{samp|{{nobr|Xend-->}}}} after it, or sometimes just {{samp|Xend-->}}, depending on browser. |
||
Comments can appear anywhere in a document, as the HTML parser is supposed to ignore them no matter where they appear so long as they are not inside other HTML tag structures. |
Comments can appear anywhere in a document, as the HTML parser is supposed to ignore them no matter where they appear so long as they are not inside other HTML tag structures (i.e., they cannot be used next to attributes and values; this is invalid markup: <code>{{nobr|<span id="x1"}}{{nobr|<--for}} "extension {{nobr|one"-->}} {{nobr|style="..."<}}</code>). |
||
Comments can even appear before the doctype declaration; no other tags are permitted to do this. |
Comments can even appear before the doctype declaration; no other tags are permitted to do this. |
||
However, not all browsers and HTML editors are fully compliant with the HTML syntax framework and may do unpredictable things under some syntax conditions. Defective handling of comments only affects about 5% of all browsers and HTML editors in use |
However, not all browsers and HTML editors are fully compliant with the HTML syntax framework and may do unpredictable things under some syntax conditions. Defective handling of comments only affects about 5% of all browsers and HTML editors in use, and even then only certain versions are affected by comment mishandling issues (Internet Explorer 6 accounts for most of this high percentage). |
||
There are a few compatibility quirks involving comments: |
There are a few compatibility quirks involving comments: |
||
* Placing comments – or indeed any characters except for white-space – before the doctype will cause Internet Explorer 6 to use [[quirks mode]] for the HTML page. None of |
* Placing comments – or indeed any characters except for white-space – before the <code>doctype</code> will cause Internet Explorer 6 to use [[quirks mode]] for the HTML page. None of the <code>doctype</code> information will be processed. |
||
* For compatibility with some pre-1995 browsers, the contents of {{ |
* For compatibility with some pre-1995 browsers, the contents of {{tag|style|o}} and {{tag|style|script|o}} elements are still sometimes surrounded by comment delimiters, and CSS- and script-capable browsers are written to specifically ignore that comment markup as not actually a comment. This means that attempts to actually comment out CSS and script markup by change the elements inside the comment to not be recognized, e.g. <code>{{nobr|<--}} {{nobr|[script]...}}[/script] {{nobr|-->}}</code>. |
||
* The [[BlueGriffon]] HTML editor, in versions 1.7.x makes comments that are not embedded in the syntax structure {{code|lang=html|code=<style> ... {comment tags} ...</style>}} show up on |
* The [[BlueGriffon]] HTML editor, in versions 1.7.{{var|x}}, makes comments that are not embedded in the syntax structure; {{code|lang=html|code=<style> ... {comment tags} ...</style>}} will show up on-screen. Other HTML editors may have this same defect. |
||
== Notes == |
== Notes == |
||
Line 987: | Line 991: | ||
===HTML standards=== |
===HTML standards=== |
||
;<span id="HTML20">HTML 2.0 |
;<span id="HTML20">HTML 2.0{{colon}}</span> |
||
:{{cite web |
:{{cite web |
||
| |
|last1=Berners-Lee |first1=Tim |author1-link=Tim Berners-Lee |
||
|last2=Connolly |first2=Dan |author2-link=Dan Connolly (computer scientist) |
|||
| title = Hypertext Markup Language - 2.0 (RFC 1866) |
|||
|title=Hypertext Markup Language - 2.0 (RFC 1866) |
|||
| |
|publisher=[[IETF]] |
||
| |
|date=November 1995 |
||
| |
|url=https://tools.ietf.org/html/rfc1866 |
||
| |
|access-date=2009-03-24}} |
||
;<span id="HTML32">HTML 3.2{{colon}}</span> |
|||
;<span id="HTML32">HTML 3.2:</span> |
|||
:{{cite web |
:{{cite web |
||
| |
|last=Raggett |first=Dave |author-link=Dave Raggett |
||
|title=HTML 3.2 Reference Specification |
|||
| first = Dave |
|||
|publisher=[[W3C]] |
|||
| authorlink = Dave Raggett |
|||
|date=1997-01-14 |
|||
| title = HTML 3.2 Reference Specification |
|||
|url= http://www.w3.org/TR/REC-html32-19970114 |
|||
| publisher = [[W3C]] |
|||
| |
|access-date=2009-03-27}} |
||
;<span id="HTML401">HTML 4.01{{colon}}</span> |
|||
| url = http://www.w3.org/TR/REC-html32-19970114 |
|||
| accessdate = 2009-03-27}} |
|||
;<span id="HTML401">HTML 4.01:</span> |
|||
:{{cite web |
:{{cite web |
||
|last=Raggett |first=Dave |author-link=Dave Raggett |
|||
| first1 = Dave |
|||
|last2=Le Hors |first2=Arnaud |
|||
| last1 = Raggett |
|||
|last3=Jacobs |first3=Ian |
|||
| last2 = Le Hors |
|||
|title=HTML 4.01 Specification |
|||
| first2 = A |
|||
|publisher=[[W3C]] |
|||
| last3 = Jacobs |
|||
|date=1999-12-24 |
|||
| first3= I. |
|||
|url= https://www.w3.org/TR/html4/ |
|||
| title = HTML 4.01 Specification |
|||
|access-date=2009-03-24}} ''(HTML 4.01 superseded [https://www.w3.org/TR/1998/REC-html40-19980424/ 4.0] (1998), which was never widely implemented, and all earlier versions. Superseded in turn on 2018-03-27 by [[#HTML52|HTML 5.2]])'' |
|||
| publisher = [[W3C]] |
|||
;<span id="XHTML10">XHTML 1.0{{colon}}</span> |
|||
| date = 1999-12-24 |
|||
| url = http://www.w3.org/TR/1999/REC-html401-19991224/ |
|||
| accessdate = 2009-03-24}} ''(HTML 4.01 is the updated form of HTML 4.0.)'' |
|||
;<span id="XHTML10">XHTML 1.0:</span> |
|||
:{{cite web |
:{{cite web |
||
| |
|author=[[W3C]] |
||
| |
|title=XHTML 1.0: The Extensible HyperText Markup Language (Second Edition) |
||
|version=Revised version |
|||
| publisher = [[W3C]] |
|||
|publisher=[[W3C]] |
|||
| date = 2000-01-26 |
|||
|date=2002-08-01 |
|||
| url = http://www.w3.org/TR/2002/REC-xhtml1-20020801 |
|||
|orig-year=2000 |
|||
| accessdate = 2009-03-24}} |
|||
|url= https://www.w3.org/TR/xhtml1/ |
|||
|access-date=2009-03-24}} |
|||
;<span id="XHTML11">XHTML 1.1:</span> |
|||
;<span id="XHTML11">XHTML 1.1{{colon}}</span> |
|||
:{{cite web |
:{{cite web |
||
| |
|editor1-last=Altheim |editor1-first=Murray |
||
|editor2-last=McCarron |editor2-first=Shane |
|||
| title = XHTML 1.1 - Module-based XHTML |
|||
|editor3-last=Ishikawa |editor3-first=Masayasu |
|||
| publisher = [[W3C]] |
|||
|title=XHTML 1.1 - Module-based XHTML - Second Edition |
|||
| date = 2001-05-31 |
|||
|version=Revised version |
|||
| url = http://www.w3.org/TR/2001/REC-xhtml11-20010531/ |
|||
|publisher=[[W3C]] |
|||
| accessdate = 2009-03-25}} |
|||
|date=2010-11-23 |
|||
|orig-year=2001 |
|||
|url= https://www.w3.org/TR/xhtml11/ |
|||
|access-date=2018-07-26}} ''(Superseded on 2018-03-27 by HTML 5.2.)'' |
|||
:<span id="XHTML11m"></span>{{cite web |
|||
|editor1-last=Austin |editor1-first=Daniel |
|||
|editor2-last=Peruvemba |editor2-first=Subramanian |
|||
|editor3-last=McCarron |editor3-first=Shane |
|||
|editor4-last=Ishikawa |editor4-first=Masayasu |
|||
|editor5-last=Birbeck |editor5-first=Mark |
|||
|editor6-last=Altheim |editor6-first=Murray |
|||
|editor7-last=Boumphrey |editor7-first=Frank |
|||
|editor8-last=Dooley |editor8-first=Sam |
|||
|editor9-last=Schnitzenbaumer |editor9-first=Sebastian |
|||
|editor10-last=Wugofski |editor10-first=Ted |
|||
|title=XHTML™ Modularization 1.1 - Second Edition |
|||
|version=Revised version |
|||
|publisher=[[W3C]] |
|||
|date=2010-07-29 |
|||
|orig-year=2006 |
|||
|url= https://www.w3.org/TR/xhtml-modularization/ |
|||
|access-date=2018-07-26}} ''(A more detailed version of the above. Also superseded on 2018-03-27 by [[#HTML52|HTML 5.2]].)'' |
|||
;<span id="HTML52">W3C HTML 5.2{{colon}}</span> |
|||
:{{cite web |
|||
|editor1-last=Faulkner |editor1-first=Steve |
|||
|editor2-last=Eicholz |editor2-first=Arron |
|||
|editor3-last=Leithead |editor3-first=Travis |
|||
|editor4-last=Danilo |editor4-first=Alex |
|||
|editor5-last=Moon |editor5-first=Sangwhan |
|||
|editor6-last=Doyle Navara |editor6-first=Erika |
|||
|editor7-last=O'Connor |editor7-first=Theresa |
|||
|editor8-last=Berjon |editor8-first=Robin |
|||
|title=HTML 5.2 W3C Recommendation |
|||
|version=Revised version |
|||
|publisher=[[W3C]] |
|||
|date=2017-12-14 |
|||
|orig-year=2016 |
|||
|url= https://www.w3.org/TR/html52/ |
|||
|access-date=2018-07-26}} ''Supersedes all previous versions of HTML and XHTML, including [https://www.w3.org/TR/html51/ HTML 5.1].'' |
|||
;<span id="WHATWGLS">WHATWG HTML5 Living Standard{{colon}}</span><!--Yes, WHATWG uses the run-together "HTML5" spelling.--> |
|||
:{{cite web |
|||
|editor-first=Ian |editor-last=Hickson |editor-link=Ian Hickson |
|||
|title=HTML Living Standard |
|||
|version=One-page Version |
|||
|publisher=[[WHATWG]] |
|||
|date=2018-07-25 |
|||
|url= https://html.spec.whatwg.org/ |
|||
|access-date=2018-07-26}} ''Also available as a [https://html.spec.whatwg.org/multipage/ Multipage Version], and [https://html.spec.whatwg.org/dev/ Developer's Edition] (also multi-page, and minus details only of interest to browser vendors).'' |
|||
===Other sources=== |
===Other sources=== |
||
;''<span id="HTMLTAGS">HTML Tags |
;''<span id="HTMLTAGS">HTML Tags{{colon}}</span>'' |
||
:{{cite web |
:{{cite web |
||
| |
|last=Berners-Lee |first=Tim |author-link=Tim Berners-Lee |
||
| |
|title=HTML Tags |
||
| |
|date=1992-11-03 |
||
| |
|url= http://www.w3.org/History/19921103-hypertext/hypertext/WWW/MarkUp/Tags.html |
||
| |
|access-date=2009-03-28}} ''(Part of the first published description of HTML.)'' |
||
;''<span id="HTMLDRAFT12">HTML Internet Draft 1.2{{colon}}</span>'' |
|||
;''<span id="HTMLDRAFT12">HTML Internet Draft 1.2:</span>'' |
|||
:{{cite web |
:{{cite web |
||
| |
|last1=Berners-Lee |first1=Tim |author1-link=Tim Berners-Lee |
||
|last2=Connolly |first2=Dan |author2-link=Dan Connolly (computer scientist) |
|||
| title = Hypertext Markup Language (HTML) |
|||
|title=Hypertext Markup Language (HTML) |
|||
| date = June 1993 |
|||
|date=June 1993 |
|||
| url = http://www.w3.org/MarkUp/draft-ietf-iiir-html-01.txt |
|||
|url= http://www.w3.org/MarkUp/draft-ietf-iiir-html-01.txt |
|||
| format = text |
|||
| |
|access-date=2009-03-28}} |
||
;''<span id="HTML30">HTML 3.0 Drafts{{colon}}</span>'' |
|||
;''<span id="HTML30">HTML 3.0 Drafts:</span>'' |
|||
:{{cite web |
:{{cite web |
||
| |
|last=Raggett |first=Dave |author-link=Dave Raggett |
||
|title=HyperText Markup Language Specification Version 3.0 (draft) |
|||
| first = Dave |
|||
|date=1995-03-24 |
|||
| title = HyperText Markup Language Specification Version 3.0 (draft) |
|||
|url= http://www.w3.org/MarkUp/html3/CoverPage.html |
|||
| date = 1995-03-24 |
|||
|access-date=2009-04-18}} ''(This is the final draft of HTML 3.0, which expired without being developed further.)'' |
|||
| url = http://www.w3.org/MarkUp/html3/CoverPage.html |
|||
;''<span id="HTMLTABLES">HTML Tables{{colon}}</span>'' |
|||
| accessdate = 2009-04-18}} ''(This is the final draft of HTML 3.0, which expired without being developed further.)'' |
|||
;''<span id="HTMLTABLES">HTML Tables:</span>'' |
|||
:{{cite web |
:{{cite web |
||
| first |
|last=Raggett |first=Dave |
||
|title=HTML Tables (RFC 1942) |
|||
| last = Raggett |
|||
|publisher=[[IETF]] |
|||
| title = HTML Tables (RFC 1942) |
|||
|date=May 1996 |
|||
| publisher = [[IETF]] |
|||
|url= https://tools.ietf.org/html/rfc1942 |
|||
| date = May 1996 |
|||
|accessdate = 2009-03-22}} |
|||
| url = //tools.ietf.org/html/rfc1942 |
|||
;<span id="XML10">XML 1.0{{colon}}</span> |
|||
| accessdate = 2009-03-22}} |
|||
;<span id="XML10">XML 1.0:</span> |
|||
:{{cite web |
:{{cite web |
||
|editor1-last=Bray |editor1-first=Tim |editor1-link=Tim Bray |
|||
| author = Bray, T, Paoli, J, Sperberg-McQueen, CM, Maler, E and Yergeau, F (editors) |
|||
|editor2-last=Paoli |editor2-first=Jean |editor2-link=Jean Paoli |
|||
| title = Extensible Markup Language (XML) 1.0 (Fifth Edition) |
|||
|editor3-last=Sperberg-McQueen |editor3-first=C. Michael |editor3-link=Michael Sperberg-McQueen |
|||
| publisher = [[W3C]] |
|||
|editor4-last=Maler |editor4-first=Eve |
|||
| date = 2008-11-26 |
|||
|editor5-last=Yergeau |editor5-first=François |
|||
| url = http://www.w3.org/TR/2008/REC-xml-20081126/ |
|||
|title=Extensible Markup Language (XML) 1.0 (Fifth Edition) |
|||
| accessdate = 2009-03-20}} |
|||
|publisher=[[W3C]] |
|||
|date=2008-11-26 |
|||
;<span id="CSS1">CSS:</span> |
|||
|url= http://www.w3.org/TR/xml/ |
|||
|access-date=2009-03-20}} |
|||
;<span id="CSS1">CSS 1{{colon}}</span> |
|||
:{{cite web |
:{{cite web |
||
|last1=Lie |first1=Håkon Wium |author1-link=Håkon Wium Lie |
|||
|author1=Lie, H.W. |author2=Bos, B. |
|||
|last2=Bos |first2=Bert |author2-link=Bert Bos |
|||
| title = Cascading Style Sheets, level 1 (revised 2008-04-11) |
|||
|title=Cascading Style Sheets, Level 1 |
|||
| publisher = [[W3C]] |
|||
|version=Revised version |
|||
| date = 2008-04-11 |
|||
|publisher=[[W3C]] |
|||
| url = http://www.w3.org/TR/CSS1/ |
|||
| |
|date=2008-04-11 |
||
|orig-year=1996 |
|||
|url= http://www.w3.org/TR/CSS1/ |
|||
|access-date=2018-07-26}} |
|||
;<span id="CSS2.1">CSS 2.1{{colon}}</span> |
|||
:{{cite web |
|||
|last1=Bos |first1=Bert |author1-link=Bert Bos |
|||
|last2=Çelik |first2=Tantek |author2-link=Tantek Çelik |
|||
|last3=Hickson |first3=Ian |author3-link=Ian Hickson |
|||
|last4=Lie |first4=Håkon Wium |author4-link=Håkon Wium Lie |
|||
|title=Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification |
|||
|version=Revised version |
|||
|publisher=[[W3C]] |
|||
|date=12 April 2016 |
|||
|orig-year=2011 |
|||
|url= https://www.w3.org/TR/CSS2/ |
|||
|access-date=2018-07-26}} |
|||
;CSS 3 and 4{{colon}} |
|||
:{{cite web |
|||
|last1=Atkins |first=Tab, Jr. |
|||
|last2=Eternad |first2=Elika J. |
|||
|last3=Rivoal |first3=Florian |
|||
|title=CSS Snapshot 2017 |
|||
|at="§ 2. Cascading Style Sheets (CSS) – The Official Definition" |
|||
|work=W3.org |
|||
|publisher=[[W3C]] |
|||
|date=31 January 2017 |
|||
|url= https://www.w3.org/TR/CSS/#css |
|||
|access-date=2018-07-26}} ''(List of active specifications that have superseded CSS 2.1, as of the publication date.)'' |
|||
:{{cite web |
|||
|author=<!--Staff writer(s); no by-line.--> |
|||
|title=CSS Current Status |
|||
|work=W3.org |
|||
|publisher=[[W3C]] |
|||
|date=2018 |
|||
|url= https://www.w3.org/standards/techs/css#w3c_all |
|||
|access-date=2018-07-26}} ''(CSS levels 3 and 4 are developed as independent modules, indexed at that page.)'' |
|||
{{refend}} |
{{refend}} |
||
Revision as of 15:20, 27 July 2018
HTML |
---|
Comparisons |
An Hyper Text Markup Language element is an individual component of an HTML document or web page, once this has been parsed into the Document Object Model. HTML is composed of a tree of HTML nodes, such as text nodes. Each node can have HTML attributes specified. Nodes can also have content, including other nodes and text. Many HTML nodes represent semantics, or meaning. For example, the <title>
node represents the title of the document.
Concepts
Document vs. DOM
HTML documents are delivered as "documents".[note 1] These are then parsed, which turns them into the Document Object Model (DOM) internal representation, within the web browser.[note 2][note 3]
Presentation by the web browser, such as screen rendering or access by JavaScript, is then performed on this internal model, not the original document.
Early HTML documents, and to a lesser extent today, were largely invalid HTML and riddled with syntax errors. The parsing process was also required to "fix-up" these errors, as best it could. The resultant model was often not correct (i.e., it did not represent what a careless coder had originally intended), but it would at least be valid, according to the HTML standard. A valid model was produced, no matter how bad the "tag soup" supplied had been. Only in the rarest cases would the parser abandon parsing altogether.
Elements vs. tags
"Elements" and "tags" are terms that are widely confused. HTML documents contain tags, but do not contain the elements. The elements are only generated after the parsing step, from these tags.[citation needed]
As is generally understood, the position of an element is indicated as spanning from a start tag, possibly including some child content, and is terminated by an end tag.[3] This is the case for many, but not all, elements within an HTML document.
As HTML is based on SGML,[4] its parsing also depends on the use of a DTD, specifically an HTML DTD such as that for HTML 4.01.[5][note 4] The DTD specifies which element types are possible (i.e. it defines the set of element types that go to make up HTML) and it also specifies the valid combinations in which they may appear in a document. It is part of general SGML behavior that where only one valid structure is possible (per the DTD), it is not generally a requirement that the document explicitly states that structure. As a simple example, the <p>
start tag indicating the start of a paragraph element should be closed by a </p>
end tag, indicating the end of the element. Also the DTD states that paragraph elements cannot be nested. The HTML document fragment:
<p>Para 1 <p>Para 2 <p>Para 3
can thus be inferred to be equivalent to:
<p>Para 1 </p><p>Para 2 </p><p>Para 3
(If one paragraph element cannot contain another, any currently open paragraph must be closed before starting another.)
Because of this implied behavior, based on the combination of the DTD and the individual document, it is not possible to infer elements from the document tags alone, but only by also using an SGML or HTML aware parser, with knowledge of the DTD.
SGML vs. XML
SGML is complex, which has limited its widespread adoption and understanding. XML was developed as a simpler alternative. XML is similar to SGML, that can also use the DTD mechanism to specify the supported elements and their permitted combinations as document structure. XML parsing is simpler. The relation from tags to elements is always that of parsing the actual tags included in the document, without the implied closures that are part of SGML.[note 5]
In Macros HTML can be formed as XML, either through XHTML or through HTML5, the parsing of document tags as DOM elements is simplified. Once the DOM of elements is obtained, behavior beyond that point (i.e. screen rendering) is identical.[note 6]
%block;
vs. box
Part of this CSS presentation behavior is the notion of the "box model". This is applied to those elements that CSS considers to be "block" elements, set through the CSS display: block;
declaration.
HTML also has a similar concept, although different, and the two are very frequently confused. %block;
and %inline;
are groups within the HTML DTD that group elements as being either "block-level" or "inline".[7] This is used to define their nesting behavior: block-level elements cannot be placed into an inline context.[note 7] This behavior cannot be changed; it is fixed in the DTD. Block and inline elements have the appropriate and different CSS behaviors attached to them by default,[7] including the relevance of the box model for particular element types.
Note though that this CSS behavior can, and frequently is, changed from the default. Lists with <ul><li> ...
are %block;
elements and are presented as block elements by default. However, it is quite common to set these with CSS to display as an inline list.[8]
Overview
Syntax
In the HTML syntax, most elements are written with a start tag and an end tag, with the content in between. An HTML tag is composed of the name of the element, surrounded by angle brackets. An end tag also has a slash after the opening angle bracket, to distinguish it from the start tag. For example, a paragraph, which is represented by the <p>
element, would be written as:
<p>In the HTML syntax, most elements are written ...</p>
However, not all of these elements require the end tag, or even the start tag, to be present. Some elements, the so-called void elements, do not have an end tag. A typical example is the <br />
(hard line-break) element. A void element's behavior is predefined, and it cannot contain any content or other elements. For example, an address would be written as:
<p>P. Sherman<br>42 Wallaby Way<br>Sydney</p>
When using an XHTML DTD, it is required to open and close the element with a single tag. To specify that it is a void element, a /
is included at the end of the tag (not to be confused with the /
at the beginning of a closing tag).
<p>P. Sherman<br />42 Wallaby Way<br />Sydney</p>
HTML attributes are specified inside the start tag. For example, the <abbr>
element, which represents an abbreviation, expects a title
attribute within its opening tag. This would be written as:
<abbr title="abbreviation">abbr.</abbr>
There are multiple kinds of HTML elements: void elements, raw text elements, and normal elements.
Void elements (also sometimes called empty elements, single elements or stand-alone elements) only have a start tag (in the form <tag />
), which contains any HTML attributes. They may not contain any children, such as text or other elements. In early versions of HTML, the slash was not required for such elements (<tag>
was permissible). The space is not required in HTML, strictly speaking (<tag/>
is valid), but is required (<tag />
) in XHTML and and other XML applications.
Two common void elements are <br />
(for a hard line-break, such as in a poem or an address) and <hr />
(for a horizontal rule). Other such elements are often place-holders which reference external files, such as the image (<img />
) element. The attributes included in the element will then point to the external file in question. Another example of a void element is <link />
, for which the syntax is:
<link rel="stylesheet" href="fancy.css" type="text/css">
This <link />
element points the browser at a style sheet to use when presenting the HTML document to the user. Note that in the HTML syntax, attributes don't have to be quoted if they are composed only of certain characters: letters, digits, the hyphen-minus and the full stop. When using the XML syntax (XHTML), on the other hand, all attributes must be quoted, and a spaced trailing slash is required before the last angle bracket:
<link rel="stylesheet" href="fancy.css" type="text/css" />
Raw text elements (also known as text or text-only elements) are constructed with:
- a start tag (in the form
<tag>
) marking the beginning of an element, which may incorporate any number of HTML attributes; - some amount of text content, but no elements (all tags, apart from the applicable end tag, will be interpreted as content);
- an end tag, in which the element name is prefixed with a slash:
</tag>
. In some versions of HTML, the end tag is optional for some elements. The end tag is required in XHTML.
An example is the <title>
element must not contain other elements (including markup of text), only plain text.
Normal elements usually have both a start tag and an end tag, although for some elements the end tag, or both tags, can be omitted. It is constructed in a similar way:
- a start tag (
<tag>
) marking the beginning of an element, which may incorporate any number of HTML attributes; - some amount of content, including text and other elements;
- an end tag, in which the element name is prefixed with a slash:
</tag>
.
HTML attributes define desired behavior or indicate additional element properties. Most attributes require a value. In HTML, the value can be left unquoted if it does not include spaces (attribute=value
), or it can be quoted with single or double quotes (attribute='value'
or attribute='value'
). In XML, those quotes are required. Boolean attributes, on the other hand, don't require a value to be specified. An example is the checked
for checkboxes:
<input type=checkbox checked>
In the XML (and thus XHTML) syntax, though, the name should be repeated as the value:
<input type="checkbox" checked="checked" />
Informally, HTML elements are sometimes referred to as "tags" (an example of synecdoche), though many prefer the term tag strictly in reference to the markup delimiting the start and end of an element.
Element (and attribute) names may be written in any combination of upper or lower case in HTML, but must be in lower case in XHTML.[9] The canonical form was upper-case until HTML 4, and was used in HTML specifications, but in recent years, lower-case has become more common.
Element standards
HTML elements are defined in a series of freely available open standards issued since 1995, initially by the IETF and subsequently by the W3C.
During the browser wars of the 1990s, developers of user agents (e.g. web browsers) often developed their own elements, some of which have been adopted in later standards. Other user agents may not recognize non-standard elements, and they will be ignored, possibly causing the page to be displayed improperly.
In 1998, XML (a simplified form of SGML) introduced mechanisms to allow anyone to develop their own elements and incorporate them in XHTML documents, for use with XML-aware user agents.[10]
Subsequently, HTML 4.01 was rewritten in an XML-compatible form, XHTML 1.0 (eXtensible HTML). The elements in each are identical, and in most cases valid XHTML 1.0 documents will be valid or nearly valid HTML 4.01 documents. This article mainly focuses on real HTML, unless noted otherwise; however, it remains applicable to XHTML. See HTML for a discussion of the minor differences between the two.
Element status
Since the first version of HTML, several elements have become outmoded, and are deprecated in later standards, or do not appear at all, in which case they are invalid (and will be found invalid, and perhaps not displayed, by validating user agents).[11]
At present, the status of elements is complicated by the existence of three types of HTML 4.01 / XHTML 1.0 DTD:
- Transitional, which contain deprecated elements, but which were intended to provide a transitional period during which authors could update their practices;
- Frameset, which are versions of the Transitional DTDs which also allow authors to write frameset documents;
- Strict, which is the up-to-date (as at 1999) form of HTML.
The first Standard (HTML 2.0) contained four deprecated elements, one of which was invalid in HTML 3.2. All four are invalid in HTML 4.01 Transitional, which also deprecated a further ten elements. All of these, plus two others, are invalid in HTML 4.01 Strict. While the frame elements are still current in the sense of being present in the Transitional and Frameset DTDs, there are no plans to preserve them in future standards, as their function has been largely replaced, and they are highly problematic for user accessibility.
(Strictly speaking, the most recent XHTML standard, XHTML 1.1 (2001), does not include frames at all; it is approximately equivalent to XHTML 1.0 Strict, but also includes the Ruby markup module.)[12]
A common source of confusion is the loose use of deprecated to refer to both deprecated and invalid status, and to elements which are expected to be formally deprecated in future.
Content vs. presentation and behavior
Since HTML 4, HTML has increasingly focused on the separation of content (the visible text and images) from presentation (like color, font size, and layout).[13] This is often referred to as a separation of concerns. HTML is used to represent the structure or content of a document, its presentation remains the sole responsibility of CSS style sheets. A default style sheet is suggested as part of the CSS standard, giving a default rendering for HTML.[14]
Behavior (interactivity) is also kept separate from content, and is handled by scripts. Images are contained in separate graphics files, separate from text, though they can also be considered part of the content of a page.
Separation of concerns allows the document to be presented by different user agents according to their purposes and abilities. For example, a user agent can select an appropriate style sheet to present a document by displaying on a monitor, printing on paper, or to determine speech characteristics in an audio-only user agent. The structural and semantic functions of the markup remain identical in each case.
Historically, user agents did not always support these features. In the 1990s, as a stop-gap, presentational elements (like <b>
}} and <i>
) were added to HTML, at the cost of creating problems for interoperability and user accessibility. This is now regarded as outmoded and has been superseded by style sheet-based design; most presentational elements are now deprecated.[15]
External image files are incorporated with the <img />
or <object />
elements. (With XHTML, the SVG language can also be used to write graphics within the document, though linking to external SVG files is generally simpler.)[16] Where an image is not purely decorative, HTML allows replacement content with similar semantic value to be provided for non-visual user agents.
An HTML document can also be extended through the use of scripts to provide additional behaviors beyond the abilities of HTML hyperlinks and forms.
The elements <style>
and <script>
, with related HTML attributes, provide style sheets and scripts.
- In the document head,
<style />
and<script />
may link to shared external documents, or<style>...</style>
and<script>...</script>
may contain embedded instructions. (The<link>
element can also be used to link style sheets.) <script />
or<script>...</script>
can occur at any point in the document (head or body).- The
style
attribute is valid in most document body elements (e.g.<div style="...">
) for inclusion of inline style instructions. - Event-handling attributes, which provide links to scripts, are optional in most elements.
- For user agents which do not operate scripts, the
<noscript>...</noscript>
element provides embedded alternative content where appropriate; however, it can only be used in the document head and in the body as a block-level element.
Document structure elements
<html>...</html>
- The root element of an HTML document; all other elements are contained in this.
- The HTML element delimits the beginning and the end of an HTML document.
- Standardized in HTML 2.0; still current.
<head>...</head>
- Container for processing information and metadata for an HTML document.
- Standardized in HTML 2.0; still current.
- (See document head elements for child elements.)
<body>...</body>
- Container for the displayable content of an HTML document.
- Standardized in HTML 2.0; still current.
- (See document body elements for child elements.)
Document head elements
<base />
- Specifies a base URL for all relative
href
and other links in the document. Must appear before any element that refers to an external resource. HTML permits only one<base>
element for each document. This element has HTML attributes, but no contents. - A development version of this element (as
BASE
) is mentioned in HTML Tags; standardized in HTML 2.0; still current.
<basefont /> (deprecated)
- Specifies a base font size, typeface, and color for the document. Used together with
<font>
elements. Deprecated in favor of style sheets. - Standardized in HTML 3.2; deprecated in HTML 4.0 Transitional; invalid in HTML 4.0 Strict.
<isindex /> (deprecated)
<isindex>
could either appear in the document head or in the body, but only once in a document. See Forms.
<link />
- Specifies links to other documents, such as previous and next links, or alternate versions.[17] A common use is to link to external style sheets, using the form:
<link rel="stylesheet" type="text/css" href="url" title="description_of_style">
[18]
- A less-common, but important, usage is to supply navigation hints consistently through use of microformats. Several common relationships are defined, that may be exposed to users through the browser interface rather than directly in the web page.
<link rel="next" href="url">
- A document's
<head>
element may contain any number of<link />
elements. This element has HTML attributes, but no contents. LINK
existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
- Can be used to specify additional metadata about a document, such as its author, publication date, expiration date, page description, keywords, or other information not provided through the other header elements and HTML attributes. Because of their generic nature,
<meta />
elements specify associative key-value pairs. In general, a meta element conveys hidden information about the document. Several meta tags can be used, all of which should be nested in the head element. The specific purpose of each<meta />
element is defined by its attributes. Outside of XHTML, it is often given without the slash (<meta>
), despite being a void element. - In one form,
<meta />
elements can specify HTTP headers which should be sent by a web server before the actual content. For example,<meta http-equiv="foo" content="bar" />
specifies that the page should be served with an HTTP header calledfoo
that has a valuebar
. - In the general form, a
<meta />
element specifiesname
and associatedcontent
HTML attributes describing aspects of the HTML page. To prevent possible ambiguity, an optional third attribute,scheme
, may be supplied to specify a semantic framework that defines the meaning of the key and its value. For example, in<meta name="foo" content="bar" scheme="DC" />
the<meta />
element identifies itself as containing thefoo
element, with a value ofbar
, from the DC or Dublin Core resource description framework. - Standardized in HTML 2.0; still current.
<object>...</object>
- Used for including generic objects within the document header. Though rarely used within a
<head>
element, it could potentially be used to extract foreign data and associate it with the current document. - Standardized in HTML 4.0; still current.
<script>...</script>
- Can act as a container for script instructions or link to an external script with the optional
src
attribute.[19] Also usable in the document body to dynamically generate either both block or inline content. - Standardized in HTML 3.2; still current.
<style>...</style>
- Specifies a style for the document, usually in the form:
<style type="text/css"> ... </style>
- Can either act as a container for style instructions or link to external style sheets – for example, in CSS, with
@import
directives of the form:<style> @import url; </style>
[20]
- Standardized in HTML 3.2; still current.
<title>...</title>
- Define a document title. Required in every HTML and XHTML document. User agents may use the title in different ways. For example:
- Web browsers usually display it in a window's title bar when the window is open, and (where applicable) in the task bar when the window is minimized.
- It may become the default file-name when saving the page.
- Web search engines' web crawlers may pay particular attention to the words used in the title.
- The
<title>
element must not contain other elements, only text. Only one<title>
element is permitted in a document. - Existed in HTML Tags, and was standardized in HTML 2.0; still current.
Document body elements
In visual browsers, displayable elements can be rendered as either block or inline. While all elements are part of the document sequence, block elements appear within their parent elements:
- as rectangular objects which do not break across lines;
- with block margins, width and height properties which can be set independently of the surrounding elements.
Conversely, inline elements are treated as part of the flow of document text; they cannot have margins, width or height set, and do break across lines.
Block elements
Block elements, or block-level elements, have a rectangular structure. By default, these elements will span the entire width of its parent element, and will thus not allow any other element to occupy the same horizontal space as it is placed on.
The rectangular structure of a block element is often referred to as the box model, and is made up of several parts. Each element contains the following:
- The content of an element is the actual text (or other media) placed between the opening and closing tags of an element.
- The padding of an element is the space around that content, which still form part of said element. Padding is physically part of an element, and should not be used to create white space between two elements. Any background style assigned to the element, such as a background image or color, will be visible within the padding. Increasing the size of an element's padding increases the amount of space this element will take up.
- The border of an element is the absolute end of an element, and spans the perimeter of that element. The thickness of a border increases the size of an element.
- The margin of an element is the white-space that surrounds an element. The content, padding and border of any other element will not be allowed to enter this area, unless forced to do so by some advanced CSS placement. Using most standard DTDs, margins on the left and right of different elements will push each other away. Margins on the top or bottom of an element, on the other hand, will not stack, or will intermingle. This means that the white-space between these elements will be as big as the larger margin between them.
The above section refers only to the detailed implementation of CSS rendering and has no relevance to HTML elements themselves.
Basic text
<p>...</p>
- Creates a paragraph, perhaps the most common block level element.
P
existed in HTML Tags, and was standardized in HTML 2.0; still current.
<h1>...</h1>
<h2>...</h2>
<h3>...</h3>
<h4>...</h4>
<h5>...</h5>
<h6>...</h6>
- Section headings at different levels.
h1
delimits the highest-level heading,h2
the next level down (sub-section),h3
for a level below that, and so on toh6
. They are sometimes referred to collectively ashn
tags, n meaning any of the available heading levels. - Most visual browsers show headings as large bold text by default, though this can be overridden with CSS. Heading elements are not intended merely for creating large or bold text – in fact, they should not be used for explicitly styling text. Rather, they describe the document’s structure and organization. Some programs use them to generate outlines and tables of contents.
- Headings existed in HTML Tags, and were standardized in HTML 2.0; still current.
Lists
<dl>...</dl>
- A description list (a.k.a. association list or description list), which consists of name–value groups,[21] and was known as a definition list prior to HTML5.[22] Description lists are intended for groups of "terms and definitions, metadata topics and values, questions and answers, or any other groups of name–value data".[23]
DL
existed in HTML Tags, and was standardized in HTML 2.0; still current.
<dt>...</dt>
- A name in a description list (previously definition term in a definition list).
DT
existed in HTML Tags, and was standardized in HTML 2.0; still current.
<dd>...</dd>
- A value in a description list (previously definition data in a definition list).
DD
existed in HTML Tags, and was standardized in HTML 2.0; still current.
<ol>...</ol>
type
attribute can be used to specify the kind of marker to use in the list, but style sheets give more control. The default is Arabic numbering. In an HTML attribute: <ol type="foo">
; or in a CSS declaration: ol { list-style-type: foo; }
– replacing foo
with one of the following:
Style | HTML value | CSS value |
---|---|---|
A, B, C ... | A |
upper-alpha
|
a, b, c ... | a |
lower-alpha
|
I, II, III ... | I |
upper-roman
|
i, ii, iii ... | i |
lower-roman
|
1, 2, 3 ... | 1 |
decimal
|
CSS provides several other options not available as pure-HTML markup, including none
, and options for CJK, Hebrew, Georgian, and Armenian script.
OL
existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<ul>...</ul>
- An unordered (bulleted) list. The type of list item marker can be specified in an HTML attribute:
<ul type="foo">
; or in a CSS declaration:ul { list-style-type: foo; }
– replacingfoo
with one of the following (the same values are used in HTML and CSS):disc
(the default),square
, orcircle
. Only the CSS method is supported in HTML5. CSS also providesnone
, and the ability to replace these bullets with custom images. UL
existed in HTML Tags, and was standardized in HTML 2.0; still current.
<li>...</li>
- A list item in ordered (
ol
) or unordered (ul
) lists. LI
existed in HTML Tags, and was standardized in HTML 2.0; still current.
<dir>...</dir> (deprecated)
- A directory listing. The original purpose of this element was never widely supported; deprecated in favor of
<ul>
. DIR
existed in HTML Tags, and was standardized in HTML 2.0; deprecated in HTML 4.0 Transitional; invalid in HTML 4.0 Strict.
Other block elements
<address>...</address>
- Contact information for the document author.
ADDRESS
existed in HTML Tags, and was standardized in HTML 2.0; still current.
<article>...</article>
- Used for articles and other similar content.
- Standardized in HTML5.
<aside>...</aside>
- Used for content in a document which is separate from the main page content, for example, sidebars or advertising.
- Standardized in HTML5.
<blockquote>...</blockquote>
- A block level quotation, for when the quotation includes block level elements, e.g. paragraphs. The
cite
attribute (not to be confused with the<cite>
element) may give the source, and must be a fully qualified Uniform Resource Identifier. - The default presentation of block quotations in visual browsers is usually to indent them from both margins. This has led to the element being unnecessarily used just to indent paragraphs, regardless of semantics. For quotations not containing block level elements see the quote (
<q>
) element. BLOCKQUOTE
existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current. See blockquote element for more information.
<center>...</center> (deprecated)
- Creates a block-level center-aligned division. Deprecated in favor of
<div>
or another element with centering defined using style sheets. - Standardized in HTML 3.2; deprecated in HTML 4.0; not supported in HTML5.
<del>...</del>
- Marks a deleted section of content. This element can also be used as inline.
- Standardized in HTML 4.0; still current.
<div>...</div>
- A block-level logical division. A generic element with no semantic meaning used to distinguish a document section, usually for purposes such as presentation or behavior controlled by style sheets or DOM calls.
- Proposed in the HTML 3.0 Drafts; Standardized in HTML 3.2; still current.
<figure>...</figure>
- Used to group images and captions, along with
<figcaption>
. - Standardized in HTML5.
<figcaption>...</figcaption>
- A caption for an image. Always placed inside the
<figure>
element. - Standardized in HTML5.
<footer>...</footer>
- Used for document footers. These might contain author or copyright information, or links to other pages.
- Standardized in HTML5.
<header>...</header>
- Used for document headers. These typically contain content introducing the page.
- Standardized in HTML5.
<hr />
- A horizontal rule. Presentational rules can also be drawn with style sheets.
- Standardized in HTML 2.0; still current.
<ins>...</ins>
- Marks a section of inserted content. This element can also be used as inline.
- Standardized in HTML 4.0; still current.
<main>...</main>
- Contains the main content of a document.
- Standardized in HTML5.
<menu>...</menu>
- HTML 2.0: A menu listing. Should be more compact than a
<ul>
list. MENU
existed in HTML Tags, and was standardized in HTML 2.0; deprecated in HTML 4.0 Transitional; invalid in HTML 4.0 Strict; but then redefined in HTML5.
<nav>...</nav>
- Used in navigational sections of articles (areas of webpages which contain links to other webpages).
- Standardized in HTML5.
<noscript>...</noscript>
- Replacement content for scripts. Unlike script this can only be used as a block-level element.
- Standardized in HTML 4.0; still current.
<pre>...</pre>
- Pre-formatted text. Text within this element is typically displayed in a non-proportional font exactly as it is laid out in the file (see ASCII art). Whereas browsers ignore white-space for other HTML elements, in
<pre>...</pre>
, white-space should be rendered as authored. (With the CSS properties:{ white-space: pre; font-family: monospace; }
, other elements can be presented in the same way.) This element can contain any inline element except:<image>
,<object>
,<big>
,<small>
,<sup>
, and<sub>...</sub>
. PRE
existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<section>...</section>
- Used for generic sections of a document. This is different from
<div>
in that it is only used to contain sections of a page, which the W3C defines as a group of content with a similar theme. - Standardized in HTML5.
<script>...</script>
- Places a script in the document. Also usable in the head and in inline contexts. It may be used as
<script />
with asrc
attribute to supply a URL from which to load the script, or used as<script>...</script>
around embedded script content.- Note:
<script>
is not itself either a block or inline element; by itself it should not display at all, but it can contain instructions to dynamically generate either both block or inline content.
- Note:
- Standardized in HTML 3.2; still current.
Inline elements
Inline elements cannot be placed directly inside the <body>
element; they must be wholly nested within block-level elements.[24]
Anchor
<a>...</a>
- An anchor element is called an anchor because web designers can use it to "anchor" a URL to some text on a web page. When users view the web page in a browser, they can click the text to activate the link and visit the page whose URL is in the link.[25]
- In HTML, an anchor can be either the origin (the anchor text) or the target (destination) end of a hyperlink.
- With the attribute
href
,[26] the anchor becomes a hyperlink to either another part of the document or another resource (e.g. a webpage) using an external URL. Alternatively (and sometimes concurrently), with thename
orid
HTML attributes set, the element becomes a link target. A Uniform Resource Locator (URL) can link to this target via a fragment identifier, commonly referred to as a "# link". In HTML5, any element can now be made into a target by using theid
attribute,[27] so using<a name="foo">...</a>
is not necessary, although this way of adding anchors continues to work. - To illustrate: the header of a table of contents section on example.com's homepage could be turned into a target by writing
<h2><a name="contents">Table of contents</a></h2>
- Continuing with this example, now that the section has been marked up as a target, it can be referred to from external sites with a link like
<a href="http://example.com#contents">see contents</a>
- or with a link on the same page like:
<a href="#contents">contents, above</a>
- The attribute
title
may be set to give brief information about the link:<a href="URL" title="additional information">link text</a>
- In most graphical browsers, when the cursor hovers over a link, the cursor changes into a hand with an extended index finger and the
title
value is displayed in a tooltip or in some other manner. Some browsers render alt text the same way, although this is not what the specification calls for. A
existed in HTML Tags, and was standardized in HTML 2.0; still current.
Phrase elements
General
<abbr>...</abbr>
- Marks an abbreviation, and can make the full form available:
<abbr title="abbreviation">abbr.</abbr>
- Standardized in HTML 4.0; still current.
<acronym>...</acronym> (deprecated)
- Similar to the
<abbr>
element, but marks an acronym:<acronym title="Hyper-Text Mark-up Language">HTML</acronym>
- Standardized in HTML 4.0; still current, not supported in HTML5.
<dfn>...</dfn>
- inline definition of a single term.
DFN
existed in HTML Internet Draft 1.2, and was fully standardized in HTML 3.2; still current.
<em>...</em>
- Emphasis (conventionally displayed in italics)
EM
existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<strong>...</strong>
- strong emphasis (conventionally displayed bold).
- An aural user agent may use different voices for emphasis.
STRONG
existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
Computer phrase elements
These elements are useful primarily for documenting computer code development and user interaction through differentiation of source code (<code>
), variables (<var>
), user input (<kbd>
), and terminal or other output (<samp>
).
<code>...</code>
- A code snippet (
code example
). Conventionally rendered in a mono-space font. CODE
existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<kbd>...</kbd>
- Keyboard – text to be entered by the user (kbd example).
KBD
existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<samp>...</samp>
- Sample output – from a program or script: (samp example).
SAMP
existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<var>...</var>
- Variable (var example).
VAR
existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
Presentation
As visual presentational markup only applies directly to visual browsers, its use is discouraged. Style sheets should be used instead. Several of these elements are deprecated or invalid in HTML 4 / XHTML 1.0, and the remainder are invalid in the current draft of XHTML 2.0. The current draft of HTML5, however, re-includes <s>
, <u>
, and <small>
, assigning new semantic meaning to each. In an HTML5 document, the use of these elements is no longer discouraged, provided that it is semantically correct.
<b>...</b>
- In HTML 4, set font to boldface where possible. Equivalent CSS:
{ font-weight: bold; }
. The<b>
element usually has the same effect in visual browsers, as well as having more semantic meaning, under HTML 4.01. - In HTML5, however,
<b>
has its own meaning, distinct from that of<strong>
. It denotes "text to which attention is being drawn for utilitarian purposes without conveying any extra importance and with no implication of an alternate voice or mood."[28] B
existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<i>...</i>
- In HTML 4, set font to italic where possible. Equivalent CSS:
{ font-style: italic; }
. Using<em>...</em>
has the same visual effect in most browsers, as well as having a semantic meaning as emphasis, under HTML 4.01. (Purely typographic italics have many non-emphasis purposes, as HTML 5 more explicitly recognized.) - In HTML5, however,
<i>
has its own semantic meaning, distinct from that of<em>
. It denotes "a different quality of text" or "an alternative voice or mood "e.g., a thought, a ship name, a binary species name, a foreign-language phrase, etc."[29] I
existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<u>...</u>
- In HTML 4, underlined text. Equivalent CSS:
{ text-decoration: underline; }
. Deprecated in HTML 4.01. Restored in HTML5. - In HTML5, the
<u>
element denotes "a span of text with an unarticulated, though explicitly rendered, non-textual annotation, such as labelling the text as being a proper name in Chinese text (a Chinese proper name mark), or labelling the text as being misspelt." The HTML5 specification reminds developers that other elements are almost always more appropriate than<u>
and admonishes designers not to use underlined text where it could be confused for a hyper-link.[30] U
existed in HTML Internet Draft 1.2, was standardized in HTML 3.2 but was deprecated in HTML 4.0 Transitional and was invalid in HTML 4.0 Strict. Reintroduced in HTML5.
<small>...</small>
- In HTML 4, decreased font size (smaller text). Equivalent CSS:
{ font-size: smaller; }
- In HTML5, the
<small>
element denotes "side comments such as small print."[31] This has caused some confusion with the<aside>...</aside>
element. - Standardized in HTML 3.2; still current.
<s>...</s>
- In HTML 4, indicated strike-through text (
Strikethrough) and was equivalent to<strike>
. - In HTML5, the
<s>
element denotes information that is "no longer accurate or no longer relevant", and is not to be confused with<del>
, which indicates removal/deletion.[32] S
was deprecated in HTML 4.0 Transitional (having not appeared in any previous standard), and was invalid in HTML 4.0 Strict. Reintroduced in HTML5, which instead deprecated<strike>
.
<big>...</big> (deprecated)
- Increased font size (bigger text). Equivalent CSS:
{ font-size: larger; }
- Standardized in HTML 3.2; not supported in HTML5.
<strike>...</strike>
- Strike-through text (
Strikethrough), (Equivalent CSS:{ text-decoration: line-through; }
) STRIKE
was standardized in HTML 3.2; deprecated in HTML 4.0 Transitional; invalid in HTML 4.0 Strict.
<tt>...</tt> (deprecated)
- Fixed-width font (typewriter-like), also known as teletype, thus "tt". (Equivalent CSS:
{ font-family: monospace; }
) TT
existed in HTML Internet Draft 1.2, and was Standardized in HTML 2.0; not supported[33] in HTML5. Possible replacements:<kbd>
for marking user input,<var>
for variables (usually rendered italic, and not with a change to monospace),<code>
for source code,<samp>
for output.[33]
<font>...</font>
<font [color=<var>color</var>] [size=<var>size</var>] [face=<var>face</var>]>...</font>
- Can specify the font color with the
color
attribute (note the American spelling), typeface with theface
attribute, and absolute or relative size with thesize
attribute. - Examples (all uses are deprecated, use CSS equivalents if possible):
<font color="green">text</font>
creates green text.<font color="#114499">text</font>
creates text with hexadecimal color #114499.<font size="4">text</font>
creates text with size 4. Sizes are from 1 to 7. The standard size is 3, unless otherwise specified in the <body> or other tags.<font size="+1">text</font>
creates text with size 1 bigger than the standard.<font size="-1">text</font>
is opposite.<font face="Courier">text</font>
makes text with Courier font.
- Equivalent CSS for font attributes:
<font size="N">
corresponds to{font-size: Yunits}
(the HTML specification does not define the relationship between size N and unit-size Y, nor does it define a unit).<font color="red">
corresponds to{ color: red; }
<font face="Times New Roman">
corresponds to{ font-family: 'Times New Roman', Times, serif; }
– CSS supports a font stack, of two or more alternative fonts.
- Standardized in HTML 3.2; deprecated in HTML 4.0 Transitional; invalid in HTML 4.0 Strict. Not part of HTML5.
Span
<span>...</span>
- An inline logical division. A generic element with no semantic meaning used to distinguish a document section, usually for purposes such as presentation or behavior controlled by style sheets or DOM calls.
- Standardized in HTML 4.0; still current.
Other inline elements
<br />
- A forced line break.
- Standardized in HTML 2.0; still current.
<bdi>...</bdi>
- Isolates an inline section of text that may be formatted in a different direction from other text outside of it, such as user-generated content with unknown directionality.
- Standardized in HTML5.
<bdo>...</bdo>
- Marks an inline section of text in which the reading direction is the opposite from that of the parent element.
- Standardized in HTML 4.0; still current.
<cite>...</cite>
- A citation or a reference for a quote or statement in the document.
- CITE existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
- Note: The HTML 5 specifications have been confusingly forked,[34] including with regard to this element. In HTML 4 and earlier,
<cite>
was for "a citation or a reference to other sources" without any particular limitations or requirements.[35] The W3C HTML 5 spec uses a refinement of this idea, reflecting how the element has historically been used, but now requiring that it contain (but not be limited to) at least one of "the title of the work or the name of the author (person, people or organization) or an URL reference, or a reference in abbreviated form as per the conventions used for the addition of citation metadata."[36] But the WHATWG spec only permits the element to be used around the title of a work.[37] The W3C specs began with the broader definition, then switched to the very narrow one after WHATWG made this change. However, W3C reverted their own change in 2012, in response to negative developer-community feedback; the element was in broadly-deployed use with the broader scope, e.g., various blog and forum platforms wrap commenters' IDs and e-mail addresses in<cite>...</cite>
, and people using the element for bibliographic citations were (and still are) routinely wrapping each entire citation in this element. - Another problem with the element is that WHATWG recommends that it be italicized by default (thus almost all browsers do so), because it (in their view) is only for publication titles. By convention, however, only certain kinds of titles actually take italics, while others are expected to be put in quotation marks, and standards may actually vary by publishing context and language. Consequently, many website authors and admins use a site-wide stylesheet to undo this element's auto-italics.
<data>...</data>
<del>...</del>
- Deleted text. Typically rendered as a strikethrough:
Deleted text. - Standardized in HTML 4.0; still current.
<ins>...</ins>
- Inserted text. Often used to mark up replacement text for material struck with
<del>
or<s>
. Typically rendered underlined: Inserted text. - Standardized in HTML 4.0; still current.
- Both
<ins>
andelements may also be used as block elements: containing other block and inline elements. However, these elements must still remain wholly within their parent element to maintain a well-formed HTML document. For example, deleting text from the middle of one paragraph across several other paragraphs and ending in a final paragraph would need to use three separate
elements. Two
elements would be required as inline elements to indicate the deletion of text in the first and last paragraphs, and a third, used as a block element, to indicate the deletion in the intervening paragraphs.
<mark>...</mark>
- Produces text that looks like this. Intended for highlighting relevant text in a quotation.
Standardized in HTML5.
<q>...</q>
- An inline quotation (for block level quotation see
<blockquote>
). Quote elements may be nested. <q>
should automatically generate quotation marks in conjunction with style sheets. Practical concerns due to browser non-compliance may force authors to find workarounds.- The
cite
attribute gives the source, and must be a fully qualified URI. - Standardized in HTML 4.0; still current.
- Note: Lengthy inline quotations may be displayed as indented blocks (as
block-quote
) using style sheets. For example, with a suitable CSS rule associated withq.lengthy
:<q>Lengthy quote here.</q >
<rb>...</rb>
- Represents the base component of a ruby annotation.
- Standardized in HTML5.[39]
<rp>...</rp>
- Provides fallback parenthesis for browsers lacking ruby annotation support.
- Standardized in HTML5.[40]
<rt>...</rt>
- Indicates pronunciation for a character in a ruby annotation.
- Standardized in HTML5.[41]
<rtc>...</rtc>
- Semantic annotations for a ruby annotation.
- Standardized in HTML5.[42]
<ruby>...</ruby>
- Represents a ruby annotation for showing the pronunciation of East Asian characters.
- Standardized in HTML5.[43]
<script>...</script>
- Places a script in the document. Also usable in the head and in block contexts.
- Note:
<script>
is not itself either a block or inline element; by itself it should not display at all, but it can contain instructions to dynamically generate either both block or inline content.
- Note:
- Standardized in HTML 3.2; still current.
<sub>...</sub>
and <sup>...</sup>
- Mark subscript or superscript text. (Equivalent CSS:
{ vertical-align: sub; }
and{ vertical-align: super; }
, respectively.) - Both were proposed in the HTML 3.0 Drafts; Standardized in HTML 3.2; still current.
<template>...</template>
- Code fragments to be copied by scripts.
- Standardized in HTML5.
<time>...</time>
- Represents a time on the 24-hour clock or a date on the Gregorian calendar, optionally with time and timezone information. Also allows times and dates to be represented in a machine-readable format.
- Standardized in HTML5.[44]
<wbr />
- An optional word break.
- Was widely used (and supported by all major browsers) for years despite being non-standard until finally being standardized in HTML5.
Images and objects
<applet>...</applet> (deprecated)
- Embeds a Java applet in the page. Deprecated in favor of
<object>
, as it could only be used with Java applets, and had accessibility limitations. - Standardized in HTML 3.2; deprecated in HTML 4.0 Transitional; invalid in HTML 4.0 Strict. As of 2011, still widely used as the implementations of the replacing
<object>
are not consistent between different browsers.
<area />
<audio>...</audio>
- Adds playable HTML5 audio to the page. The audio URL is determined using the
src
attribute. Supported audio formats vary from browser to browser. - Standardized in HTML5.
<canvas>...</canvas>
- Adds a canvas whose contents can be edited with JavaScript. Frequently used for online games.
- Standardized in HTML5.
<embed>...</embed>
- Inserts a non-standard object (like applet) or external content (typically non-HTML) into the document. Deprecated in HTML 4 in favor of
<object>
, but then was added back into the HTML5 specification[45][46]
<img />
- Used by visual user agents to insert an image in the document. The
src
attribute specifies the image URL. The requiredalt
attribute provides alternative text in case the image cannot be displayed.[47] (Thoughalt
is intended as alternative text, Microsoft Internet Explorer 7 and below render it as a tooltip if notitle
attribute is given.[48] Safari and Google Chrome, on the other hand, do not display the alt attribute at all.)[49] The<img />
element was first proposed by Marc Andreessen and implemented in the NSCA Mosaic web browser.[50] IMG
existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<map>...</map>
<object>...</object>
- Includes an object in the page of the type specified by the
type
attribute. This may be in any MIME-type the user agent understands, such as an embedded HTML page, a file to be handled by a plug-in such as Flash, a Java applet, a sound file, etc. - Standardized in HTML 4.0; still current.
<param />
- Originally introduced with applet}, this element is now used with, and should only occur as a child of
<object>
. It uses HTML attributes to set a parameter for the object, e.g. width, height, font, background color, etc., depending on the type of object. An object can have multiple<param />
elements. - Standardized in HTML 3.2; still current.
<source>...</source>
- Specifies different sources for audio or video. Makes use of the
src
attribute in a way similar to the<video>
and<audio>
elements. - Standardized in HTML5.
<track>...</track>
- Provides text tracks, like subtitles and captions, for audio and video.
- Standardized in HTML5.
<video>...</video>
- Adds a playable HTML5 video to the page. The video URL is determined using the
src
attribute. Supported video formats vary from browser to browser. - Standardized in HTML5.
Forms
These elements can be combined into a form or in some instances used separately as user-interface controls; in the document, they can be simple HTML or used in conjunction with Scripts. HTML markup specifies the elements that make up a form, and the method by which it will be submitted. However, some form of scripts (server-side, client-side, or both) must be used to process the user’s input once it is submitted.
(These elements are either block or inline elements, but are collected here as their use is more restricted than other inline or block elements.)
<form action="url">...</form>
- Creates a form. The
<form>
element specifies and operates the overall action of a form area, using the requiredaction
attribute. - Standardized in HTML 2.0; still current.
<button>...</button>
- A generic form button which can contain a range of other elements to create complex buttons.
- Standardized in HTML 4.0; still current.
<datalist>...</datalist>
- A list of
option
s for use in form elements. - Standardized in HTML5.
<fieldset>...</fieldset>
- A container for adding structure to forms. For example, a series of related controls can be grouped within a
<fieldset>
, which can then have a<legend>
added in order to identify their function. - Standardized in HTML 4.0; still current.
<input />
<input>
elements allow a variety of standard form controls to be implemented.- Standardized in HTML 2.0; still current.
- Input Types:
- type="checkbox"
- A checkbox. Can be checked or unchecked.
- type="radio"
- A radio button. If multiple radio buttons are given the same name, the user will only be able to select one of them from this group.
- type="button"
- A general-purpose button. The element
<button>
is preferred if possible (i.e., if the client supports it) as it provides richer possibilities.
- A general-purpose button. The element
- type="submit"
- A submit button.
- type="image"
- An image button. The image URL may be specified with the
src
attribute.
- An image button. The image URL may be specified with the
- type="reset"
- A reset button for resetting the form to default values.
- type="text"
- A one-line text input field. The
size
attribute specifies the default width of the input in character-widths.max-length
sets the maximum number of characters the user can enter (which may be greater than size).
- A one-line text input field. The
- type="search"
- A variation of
text
which produces a search bar.
- A variation of
- type="password"
- A variation of
text
. The difference is that text typed in this field is masked – characters are displayed as an asterisk, a dot, or another replacement. The password is still submitted to the server as plaintext, so an underlying secure communication protocol like HTTPS is needed if confidentiality is a concern.
- A variation of
- type="file"
- A file select field (for uploading files to a server).
- type="tel"
- A variation of
text
for telephone numbers.
- A variation of
- type="email"
- A variation of
text
for email addresses.
- A variation of
- type="url"
- A variation of
text
for URLs.
- A variation of
- type="date"
- A date selector.
- type="time"
- A time selector.
- type="number"
- A variation of
text
for numbers.
- A variation of
- type="range"
- Produces a slider for that returns a number, but the number is not visible to the user.
- type="color"
- A color picker.
- type="hidden"
hidden
inputs are not visible in the rendered page, but allow a designer to maintain a copy of data that needs to be submitted to the server as part of the form. This may, for example, be data that this web user entered or selected on a previous form that needs to be processed in conjunction with the current form. Not displayed to the user but data can still be altered client-side by editing the HTML source.
<isindex /> (deprecated)
<isindex />
could either appear in the document head or in the body, but only once in a document.<isindex />
operated as a primitive HTML search form; but was de facto obsoleted by more advanced HTML forms introduced in the early to mid-1990s. Represents a set of hyperlinks composed of a base URI, an ampersand and percent-encoded keywords separated by plus signs.ISINDEX
existed in HTML Tags; standardized in HTML 2.0; deprecated in HTML 4.0 Transitional; invalid in HTML 4.0 Strict.
<keygen>...</keygen>
- A key pair generator.
- Standardized in HTML5.
<label for="id">...</label>
- Creates a label for a form input, such as
radio
. Clicking on the label fires a click on the matching input. - Standardized in HTML 4.0; still current.
<legend>...</legend>
- A legend (caption) for a
<fieldset>
. - Standardized in HTML 4.0; still current.
<meter>...</meter>
- A meter which needs a
value
attribute. Can also have:min
,low
,high
, andmax
. - Standardized in HTML5.
<option value="x">...</option>
- Creates an item in a
<select>
list. - Standardized in HTML 2.0; still current.
<optgroup>...</optgroup>
- Identifies a group of
<option>
elements in a<select>
list. - Standardized in HTML 4.0; still current.
<output>...</output>
- The value of a form element.
- Standardized in HTML5.
<progress>...</progress>
- A bar for showing the progress of an action.
- Standardized in HTML5.
<select name="xyz">...</select>
- Creates a selection list, from which the user can select a single option. May be rendered as a dropdown list.
- Standardized in HTML 2.0; still current.
<textarea rows="8">...</textarea>
- A multiple-line text area, the size of which is specified by
cols
(where a column is a one-character width of text) androws
HTML attributes. The content of this element is restricted to plain text, which appears in the text area as default text when the page is loaded. - Standardized in HTML 2.0; still current.
Tables
The format of HTML Tables was proposed in the HTML 3.0 Drafts and the later RFC 1942 HTML Tables. They were inspired by the CALS Table Model. Some elements in these proposals were included in HTML 3.2; the present form of HTML Tables was standardized in HTML 4. (Many of the elements used within tables are neither block nor inline elements.)
<table>...</table>
- Identifies a table. Several HTML attributes are possible in HTML Transitional, but most of these are invalid in HTML Strict and can be replaced with style sheets. The
summary
attribute is informally required for accessibility purposes, though its usage is not simple. - Proposed in the HTML 3.0 Drafts; Standardized in HTML 3.2; still current.
<tr>...</tr>
- Contains a row of cells in a
<table>
. - Proposed in the HTML 3.0 Drafts; Standardized in HTML 3.2; still current.
<th>...</th>
- A
<table>
header cell; contents are conventionally displayed bold and centered. An aural user agent may use a louder voice for these items. - Proposed in the HTML 3.0 Drafts; Standardized in HTML 3.2; still current.
<td>...</td>
- A
<table>
data cell. - Proposed in the HTML 3.0 Drafts; Standardized in HTML 3.2; still current.
<colgroup>...</colgroup>
- Specifies a column group in a
<table>
. - Proposed in HTML Tables; Standardized in HTML 4.0; still current.
<col>...</col>
- Specifies a column in a
<table>
. - Proposed in HTML Tables; Standardized in HTML 4.0; still current.
<caption>...</caption>
- Specifies a caption for a
<table>
. - Proposed in the HTML 3.0 Drafts; Standardized in HTML 3.2; still current.
<thead>...</thead>
- Specifies the header part of a
<table>
. This section may be repeated by the user agent if the table is split across pages (in printing or other paged media). - Proposed in HTML Tables; Standardized in HTML 4.0; still current.
<tbody>...</tbody>
- Specifies a body of data for a
<table>
. - Proposed in HTML Tables; Standardized in HTML 4.0; still current.
<tfoot>...</tfoot>
- Specifies the footer part of a
<table>
. Like<thead>
, this section may be repeated by the user agent if the table is split across pages (in printing or other paged media). - Proposed in HTML Tables; Standardized in HTML 4.0; still current.
Frames
Frames allow a visual HTML Browser window to be split into segments, each of which can show a different document. This can lower bandwidth use, as repeating parts of a layout can be used in one frame, while variable content is displayed in another. This may come at a certain usability cost, especially in non-visual user agents,[51] due to separate and independent documents (or websites) being displayed adjacent to each other and being allowed to interact with the same parent window. Because of this cost, frames (excluding the <iframe>
element) are only allowed in HTML 4.01 Frame-set. Iframes can also hold documents on different servers. In this case the interaction between windows is blocked by the browser. Sites like Facebook and Twitter use iframes to display content (plugins) on third party websites. Google AdSense uses iframes to display banners on third party websites.
In HTML 4.01, a document may contain a <head>
and a <body>
} or a <head>
and a <frameset>
, but not both a <body>
and a <frameset>
. However, <iframe>
can be used in a normal document body.
<frameset>...</frameset> (deprecated)
- Contains the set of
<frame />
elements for a document. The layout of frames is given by comma separated lists in therows
andcols
HTML attributes. - Standardized in HTML 4.0 Frameset, obsolete in HTML5.
<frame /> (deprecated)
- Defines a single frame, or region, within the
<frameset>
. A separate document is linked to a frame using thesrc
attribute inside the<frame />
element. - Standardized in HTML 4.0 Frameset, obsolete in HTML5.
<noframes>...</noframes> (deprecated)
- Contains normal HTML content for user agents that don't support
<frame />
elements. - Standardized in HTML 4.0 Transitional, obsolete in HTML5.
<iframe>...</iframe>
- An inline frame places another HTML document in a frame. Unlike an
<object />
element, an<iframe>
can be the "target" frame for links defined by other elements, and it can be selected by the user agent as the focus for printing, viewing its source, and so on. - The content of the element is used as alternative text to be displayed if the browser does not support inline frames.
- First introduced by Microsoft Internet Explorer in 1997, standardized in HTML 4.0 Transitional, allowed in HTML5.
longdesc
attribute
In HTML, longdesc
is an attribute used within the <img />
, <frame />
, or <iframe>
elements. It is supposed to be a URL[note 8] to a document that provides a long description for the image, frame, or iframe in question.[52] Note that this attribute should contain a URL, and not – as is commonly mistaken – the text of the description itself.
longdesc
was designed to be used by screen readers to display image information for computer users with accessibility issues, such as the blind or visually impaired, and is widely implemented by both web browsers and screen readers.[53] Some developers object that
[54] it is actually seldom used for this purpose because there are relatively few authors who use the attribute and most of those authors use it incorrectly; thus, they recommend deprecating longdesc
.[55] The publishing industry has responded, advocating the retention of longdesc
.[56]
Example
<img src="Hello.jpg" longdesc="description.html">
Content of description.html
:
<br />
<p>This is an image of a two-layered birthday cake.</p>
...
Linking to the long description in the text
Since very few graphical browsers support making the link available natively (Opera and iCab being the exceptions), it is useful to include a link to the description page near the <img />
element whenever possible, as this can also aid sighted users.
Example
<img src="Hello.jpg" longdesc="description.html" /> [<a href=
"description.html" title="long description of the image">D</a>]
Historic elements
The following elements were part of the early HTML developed by Tim Berners-Lee from 1989–91; they are mentioned in HTML Tags, but deprecated in HTML 2.0 and were never part of HTML standards.
<listing>...</listing> (deprecated)
- This element displayed the text inside the tags in a monospace font and without interpreting the HTML. The HTML 2.0 specification recommended rendering the element at up to 132 characters per line.
- Deprecated in HTML 3.2; obsolete in HTML5.[57]
<plaintext /> (deprecated)
<plaintext />
does not have an end tag as it terminates the markup and causes the rest of the document to be parsed as if it were plaintext.<plaintext />
existed in HTML Tags; deprecated in HTML 2.0; invalid in HTML 4.0.
<xmp>...</xmp> (deprecated)
- This element displayed the text inside the tags in a monospace font and without interpreting the HTML. The HTML 2.0 specification recommended rendering the element at 80 characters per line.
- Deprecated in HTML 3.2; obsolete in HTML5.[58]
<nextid /> (deprecated)
- This element enabled NeXT web designing tool to generate automatic NAME labels for its anchors and was itself automatically generated.[59]
<nextid />
existed in HTML Tags (described as obsolete); deprecated in HTML 2.0; invalid in HTML 3.2 and later.
Non-standard elements
This section lists some widely used obsolete elements, which means they are not used in valid code. They may not be supported in all user agents.
<blink>...</blink> (deprecated)
- Causes text to blink. Introduced in imitation of the ANSI escape codes. Can be done with CSS where supported:
{text-decoration: blink}
(This effect may have negative consequences for people with photosensitive epilepsy;[60] its use on the public Internet should follow the appropriate guidelines.) <blink>
originated in Netscape Navigator and is mostly recognized by its descendants, including Firefox; deprecated or invalid in HTML 2.0 and later. Note that the replacement CSS tag, while standard, is not required to be supported.
<marquee>...</marquee> (deprecated)
- Creates scrolling text. Can be done with scripting instead. (This effect may have negative consequences for people with photosensitive epilepsy;[60] its use on the public Internet should follow the appropriate guidelines.) There are three options, including Alternate, Scroll and slide. Scrolldelay can also be added.
<marquee>
originated in Microsoft Internet Explorer; deprecated or invalid in HTML 4.01 and later.
<nobr>...</nobr> (deprecated)
- Causes text to not break at end of line, preventing word wrap where text exceeds the width of the enclosing object. Adjacent text may break before and after it. Can be done with CSS:
{white-space: nowrap;}
<nobr>
is a proprietary element which is recognized by most browsers for compatibility reasons; deprecated or invalid in HTML 2.0 and later.
<noembed>...</noembed> (deprecated)
- Specifies alternative content, if the embed cannot be rendered. Replaced by the content of the
<embed>
or<object>
element.
Comments
<!-- A Comment -->
A comment in HTML (and related XML, SGML and SHTML) uses the same syntax as the SGML comment or XML comment, depending on the doctype.
Unlike most HTML tags, comments do not nest.
The markup <!--Xbegin<!--Y-->Xend-->
will yield the comment Xbegin<!--Y and the text Xend--> after it, or sometimes just Xend-->, depending on browser.
Comments can appear anywhere in a document, as the HTML parser is supposed to ignore them no matter where they appear so long as they are not inside other HTML tag structures (i.e., they cannot be used next to attributes and values; this is invalid markup: {{{1}}}<--for "extension one"--> {{{1}}}
).
Comments can even appear before the doctype declaration; no other tags are permitted to do this.
However, not all browsers and HTML editors are fully compliant with the HTML syntax framework and may do unpredictable things under some syntax conditions. Defective handling of comments only affects about 5% of all browsers and HTML editors in use, and even then only certain versions are affected by comment mishandling issues (Internet Explorer 6 accounts for most of this high percentage).
There are a few compatibility quirks involving comments:
- Placing comments – or indeed any characters except for white-space – before the
doctype
will cause Internet Explorer 6 to use quirks mode for the HTML page. None of thedoctype
information will be processed. - For compatibility with some pre-1995 browsers, the contents of
<style>
andelements are still sometimes surrounded by comment delimiters, and CSS- and script-capable browsers are written to specifically ignore that comment markup as not actually a comment. This means that attempts to actually comment out CSS and script markup by change the elements inside the comment to not be recognized, e.g.
<-- [script]...[/script] -->
. - The BlueGriffon HTML editor, in versions 1.7.x, makes comments that are not embedded in the syntax structure;
<style> ... {comment tags} ...</style>
will show up on-screen. Other HTML editors may have this same defect.
Notes
- ^ "Document" may refer interchangeably to either a file stored on a computer filesystem, usually on disk, or to a document delivered across the Web by HTTP. Such documents may equally be copies of disk files stored on the web server, or they may be generated on demand.
- ^ Document Object Model is now a formalized specification by the W3C.[1] It defines an interface to this internal model, rather than the internal model itself. Early web browsers used their own internal representation that bore little relation to the DOM. The term "document tree" has also been applied.[2] However for the purpose here, of explaining the difference between a document of tags and a parsed model of elements, it is convenient to use the term DOM throughout.
- ^ The term "web browser" here is used for simplicity. It does of course include other sorts of web user agent, such as search engine web crawlers, automatic news-feed retrievers etc.
- ^ HTML 4.01 is one of a small number of well-known HTML DTDs. It is chosen here as the best illustrative example, although the same behavior applies to the other W3C-published DTDs for HTML.
- ^ A macro-like feature of DTDs may still be used within XML.
- ^ One minor point is that XML, even after the DOM interface, is case-sensitive.[6]
- ^ However, see
<object>
for the inevitable exception. - ^ Strictly an IRI, not a URL; although URLs are a subset of IRIs.
References
- ^ "Document Object Model (DOM) Current Version". W3C. 26 July 2016.
- ^ "Definitions – Document tree". Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification. W3C. 7 June 2011. "§ 3 Conformance: Requirements and Recommendations".
- ^ "§ 3 On SGML and HTML". HTML 4.01 Specification. W3C. 24 December 1999. "§ 3.2.1 Elements".
- ^ "§ 3 On SGML and HTML". HTML 4.01 Specification. W3C. 24 December 1999. "§ 3.1 Introduction to SGML".
- ^ "HTML 4.01, § 21, Document Type Definition". W3C. 24 December 1999.
- ^ "§ 1. Document Object Model HTML". Document Object Model (DOM) Level 2 HTML Specification. W3C. 9 January 2003. "§ 1.3. XHTML and the HTML DOM".
- ^ a b "§ 7 The global structure of an HTML document". HTML 4.01 Specification. W3C. 24 December 1999. "§ 7.5.3 Block-level and inline elements".
- ^ Mark Newhouse (27 September 2002). "CSS Design: Taming Lists". A List Apart.
- ^ XHTML 1.0 § 4.2
- ^ XML 1.0 (The ability to produce additional elements is part of the eXtensibility in the acronym.)
- ^ XML 1.0 § 5.1
- ^ XHTML 1.1 § A
- ^ "HTML & CSS". W3C. 2013.
- ^ "Appendix D. Default style sheet for HTML 4". Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification. W3C. 7 June 2011.
- ^ HTML 4.01 § 14.1
- ^ Ferraiolo, J.; Fujisawa, J.; Jackson, D., eds. (2003-01-14). "§ 2.3 Options for using SVG in Web pages". Scalable Vector Graphics (SVG) 1.1 Specification. W3C. Retrieved 2009-03-25.
- ^ HTML 4.01 § 12.3
- ^ HTML 4.01 § 14.3.2
- ^ HTML 4.01 § 18
- ^ CSS § 1.1
- ^ "4.4 Grouping content – HTML5". HTML5: A vocabulary and associated APIs for HTML and XHTML – W3C Recommendation. World Wide Web Consortium. 28 October 2014. "§ 4.4.8 The dl element". Retrieved 16 August 2015.
- ^ "Lists in HTML documents". HTML 4.01 Specification – W3C Recommendation. World Wide Web Consortium. 24 December 1999. "§ 10.3 Definition lists: the DL, DT, and DD elements". Retrieved 2 May 2015.
- ^ W3C (5 April 2011). "HTML5: A Vocabulary and Associated APIs for HTML and XHTML, W3C Working Draft".
{{cite web}}
: CS1 maint: numeric names: authors list (link). - ^ HTML 4.01, W3.org, retrieved 2012-03-26
- ^ HTML 4 for dummies, 5th ed., 2005, by Ed Tittel, Mary C. Burmeister; p. 96.
- ^ "ServerWriter -- /Provider". www.w3.org.
- ^ "HTML 5.2". w3.org.
- ^ 4.6 Text-level semantics — The b element, Developers.whatwg.org, retrieved 2012-03-26
- ^ 4.6 Text-level semantics — The i element, Developers.whatwg.org, retrieved 2012-03-26
- ^ 4.6 Text-level semantics — The u element, Developers.whatwg.org, retrieved 2012-03-26
- ^ 4.6 Text-level semantics — The small element, Developers.whatwg.org, retrieved 2012-03-26
- ^ 4.6 Text-level semantics — The s element, Developers.whatwg.org, retrieved 2012-03-26
- ^ a b 11 Obsolete features — HTML5, W3.org, retrieved 2012-03-26
- ^ "HTML5 specification finalized, squabbling over specs continues". Ars Technica. 29 October 2014. Retrieved 29 October 2014.
- ^ "9.2.1 Phrase elements: EM, STRONG, DFN, CODE, SAMP, KBD, VAR, CITE, ABBR, and ACRONYM". HTML 4.01 Specification. W3C. 24 December 1999. Retrieved 26 July 2018.
- ^ HTML 5.2 W3C Recommendation, at "§ 4.5.6. The cite element".
- ^ HTML Living Standard, at "§ 4.5.6 The cite element".
- ^ "<data>". MDN Web Docs.
- ^ "HTML
Tag" . www.quackit.com. - ^ "<rp>: The Ruby Fallback Parenthesis element". MDN Web Docs.
- ^ "<rt>: The Ruby Text element". MDN Web Docs.
- ^ "<rtc>: The Ruby Text Container element". MDN Web Docs.
- ^ "<ruby>". MDN Web Docs.
- ^ "<time>". MDN Web Docs.
- ^ Jennifer Kyrnin
<embed>
- ^ W3Schools about
<embed>
- ^ The alt attribute's text cannot be styled with markup; as a result, other methods of alternative text presentation, such as Fahrner Image Replacement, have been devised to accommodate situations in which the coder wishes styled text to be displayed if images are disabled in a user's browser.
- ^ "What's New in Internet Explorer 8 – Accessibility and ARIA". MSDN. Microsoft. Retrieved 2009-07-22.
- ^ Bug 5566 – ALT attribute value sometimes not displayed when image is missing, Bugs.webkit.org, retrieved 2012-03-26
- ^ WWW-Talk Jan-Mar 1993: proposed new tag: IMG, 1997.webhistory.org, retrieved 2012-03-26
- ^ "Are frames accessible?".
...frames do present additional usability challenges that are unique to users with disabilities, particularly those who use screen readers.
- ^ "Objects, Images, and Applets". W3C. Retrieved 2008-12-20.
- ^ "InState Longdesc". Retrieved 2011-09-05.
- ^ "Creating Accessible Images". WebAim. Retrieved 2008-12-20.
- ^ Longdesc usage - WHATWG Wiki, Wiki.whatwg.org, retrieved 2012-03-26
- ^ "Bug 13461 - Commentary on Issue #30 (longdesc) from the Association of American Publishers". Retrieved 2011-09-05.
- ^ "<listing>". MDN Web Docs.
- ^ "<xmp>". MDN Web Docs.
- ^ "<nextid>: The NeXT ID element (Obsolete)". MDN Web Docs.
- ^ a b Chisholm, Wendy; Vanderheiden, Gregg; Jacobs, Ian (1999-05-05). "Web Content Accessibility Guidelines 1.0". World Wide Web Consortium. Retrieved 2010-07-20.
Bibliography
HTML standards
- HTML 2.0:
- Berners-Lee, Tim; Connolly, Dan (November 1995). "Hypertext Markup Language - 2.0 (RFC 1866)". IETF. Retrieved 2009-03-24.
- HTML 3.2:
- Raggett, Dave (1997-01-14). "HTML 3.2 Reference Specification". W3C. Retrieved 2009-03-27.
- HTML 4.01:
- Raggett, Dave; Le Hors, Arnaud; Jacobs, Ian (1999-12-24). "HTML 4.01 Specification". W3C. Retrieved 2009-03-24. (HTML 4.01 superseded 4.0 (1998), which was never widely implemented, and all earlier versions. Superseded in turn on 2018-03-27 by HTML 5.2)
- XHTML 1.0:
- W3C (2002-08-01) [2000]. "XHTML 1.0: The Extensible HyperText Markup Language (Second Edition)". Revised version. W3C. Retrieved 2009-03-24.
{{cite web}}
: CS1 maint: numeric names: authors list (link) - XHTML 1.1:
- Altheim, Murray; McCarron, Shane; Ishikawa, Masayasu, eds. (2010-11-23) [2001]. "XHTML 1.1 - Module-based XHTML - Second Edition". Revised version. W3C. Retrieved 2018-07-26. (Superseded on 2018-03-27 by HTML 5.2.)
- Austin, Daniel; Peruvemba, Subramanian; McCarron, Shane; Ishikawa, Masayasu; Birbeck, Mark; Altheim, Murray; Boumphrey, Frank; Dooley, Sam; Schnitzenbaumer, Sebastian; Wugofski, Ted, eds. (2010-07-29) [2006]. "XHTML™ Modularization 1.1 - Second Edition". Revised version. W3C. Retrieved 2018-07-26. (A more detailed version of the above. Also superseded on 2018-03-27 by HTML 5.2.)
- W3C HTML 5.2:
- Faulkner, Steve; Eicholz, Arron; Leithead, Travis; Danilo, Alex; Moon, Sangwhan; Doyle Navara, Erika; O'Connor, Theresa; Berjon, Robin, eds. (2017-12-14) [2016]. "HTML 5.2 W3C Recommendation". Revised version. W3C. Retrieved 2018-07-26. Supersedes all previous versions of HTML and XHTML, including HTML 5.1.
- WHATWG HTML5 Living Standard:
- Hickson, Ian, ed. (2018-07-25). "HTML Living Standard". One-page Version. WHATWG. Retrieved 2018-07-26. Also available as a Multipage Version, and Developer's Edition (also multi-page, and minus details only of interest to browser vendors).
Other sources
- HTML Tags:
- Berners-Lee, Tim (1992-11-03). "HTML Tags". Retrieved 2009-03-28. (Part of the first published description of HTML.)
- HTML Internet Draft 1.2:
- Berners-Lee, Tim; Connolly, Dan (June 1993). "Hypertext Markup Language (HTML)". Retrieved 2009-03-28.
- HTML 3.0 Drafts:
- Raggett, Dave (1995-03-24). "HyperText Markup Language Specification Version 3.0 (draft)". Retrieved 2009-04-18. (This is the final draft of HTML 3.0, which expired without being developed further.)
- HTML Tables:
- Raggett, Dave (May 1996). "HTML Tables (RFC 1942)". IETF. Retrieved 2009-03-22.
- XML 1.0:
- Bray, Tim; Paoli, Jean; Sperberg-McQueen, C. Michael; Maler, Eve; Yergeau, François, eds. (2008-11-26). "Extensible Markup Language (XML) 1.0 (Fifth Edition)". W3C. Retrieved 2009-03-20.
- CSS 1:
- Lie, Håkon Wium; Bos, Bert (2008-04-11) [1996]. "Cascading Style Sheets, Level 1". Revised version. W3C. Retrieved 2018-07-26.
- CSS 2.1:
- Bos, Bert; Çelik, Tantek; Hickson, Ian; Lie, Håkon Wium (12 April 2016) [2011]. "Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification". Revised version. W3C. Retrieved 2018-07-26.
- CSS 3 and 4:
- Atkins, Tab, Jr.; Eternad, Elika J.; Rivoal, Florian (31 January 2017). "CSS Snapshot 2017". W3.org. W3C. "§ 2. Cascading Style Sheets (CSS) – The Official Definition". Retrieved 2018-07-26.
{{cite web}}
: CS1 maint: multiple names: authors list (link) (List of active specifications that have superseded CSS 2.1, as of the publication date.) - "CSS Current Status". W3.org. W3C. 2018. Retrieved 2018-07-26. (CSS levels 3 and 4 are developed as independent modules, indexed at that page.)
External links
- HTML 4.01 (Dec 24, 1999): elements and attributes
- HTML5 (Oct 28, 2014): elements and attributes