The Wikipedia:Superfluous bolding explained page is a Wikipedia page explaining superfluous bolding. That is, how not to awkwardly, superfluously cram an article's title in bold into its first sentence, producing awkward phrasing and circular definitions.
Wikipedia articles often have a consistent structure, and editors tend to mimic the structures of other articles ("monkey see, monkey do") while writing, often without realizing why those article structures exist in the first place. By a long-standing convention formalized in the Manual of Style, name of the article subject is typically repeated in the first sentence, usually providing a definition, and displayed in bold. However, that is not mandatory and should be applied only where it fits the natural sentence structure.
Appropriate bolding
In many cases, an article's subject has a given name or commonly accepted terminology. Topics like "apple", "John Henry", "World War II", and "bluejacking" all have given names. In this case, the article's title (which is also the name of the article's subject) is mentioned at the earliest natural point in the first sentence of the article. This name and any other names for the topic (synonyms) are bolded to help readers recognize what they are looking at, especially if they've visited from a synonym's disambiguation page:
The United Kingdom of Great Britain and Northern Ireland (usually shortened to the United Kingdom or UK) occupies part of the British Isles in north-western Europe ...
Superfluous bolding
But Wikipedia is not a dictionary, and articles are focused on topics, not terms. Since the term "saturn" is used for many different unrelated topics, for instance, we give each a separate article. This also means that Wikipedia has articles about topics that don't necessarily have their own names. Examples include "Electrical characteristics of dynamic loudspeakers", "Effects of Hurricane Katrina in New Orleans", "1921 in Afghanistan", and "Parity of zero". In other words, the title of the article is merely a description of the article topic, not a given name.
Trying to mimic other articles, editors will often try to fit such a title in the first sentence and bold it, leading to tautology:
The electrical characteristics of a dynamic loudspeaker are a dynamic loudspeaker driver's electrical characteristics, the chief one of which is ...
...or awkward phrasing:
The Selarang Barracks Incident, also known as the Barrack Square Incident, was an incident on ...
It also gives undue weight to the chosen title, implying that it is an official term, commonly accepted name, or the only acceptable title, when it is actually just a description and the event or topic is given many different names in common usage:
The January 31, 2007, Boston bomb scare occurred when Boston police officers mistakenly identified ...
So, in the case of purely descriptive titles, we should not bold the article title in the introduction, and there is no need to repeat it verbatim at the beginning of the article and fit an awkwardly worded sentence around it:
The chief electrical characteristic of a dynamic loudspeaker's driver is ...