Do not capitalize the second or subsequent words in an article title, unless the title is a proper noun. For multiword page titles, one should leave the second and subsequent words in lowercase unless the title phrase is a proper noun that would always occur capitalized, even in the middle of a sentence.

This convention often also applies within the article body, as there is usually no good reason to use capitals. Outside Wikipedia, and within certain specific fields (such as medicine), the usage of all-capital terms may be a proper way to feature new or important items. However these cases are typically examples of buzzwords, which by capitalization are (improperly) given featured status.

In general, each word in English titles of books, films, and other works takes an initial capital, except for articles ("a", "an", "the"), the word "to" as part of an infinitive, prepositions and coordinating conjunctions shorter than five letters (e.g., "on", "from", "and", "with"), unless they begin or end a title or subtitle. Examples: A New Kind of Science, Ghost in the Shell, To Be or Not to Be, The World We Live In. For details, see Wikipedia:Manual of Style (capital letters)#Composition titles.

Because credibility is a primary objective in the creation of any reference work, and because Wikipedia strives to become a leading (if not the leading) reference work in its genre, formality and an adherence to conventions widely used in the genre are critically important to credibility. See these recommended reference works for capitalization conventions:

• The Chicago Manual of Style;
• Fowler's Modern English Usage (Third edition);

The software treats all article titles as beginning with a capital letter (unless the first character is not a letter). For information on how to display article titles beginning with lower-case letters (as in eBay), see Wikipedia:Naming conventions (technical restrictions)#Lowercase first letter.

However, when you create a link with the first letter of the link uncapitalized, like this, the first letter of the target page is automatically capitalized by the software. So like this points to the page titled "Like this". However, the remainder of the link (after the initial character) is case-sensitive.

Searching using the "Go" or "Search" button is generally speaking case-insensitive. It is not necessary to create redirects from alternative capitalizations, unless editors are likely to link from a differently capitalized form. For example, "National Park" should be created as a redirect to National park, but it is unnecessary to create "Isle of wight" as a redirect to Isle of Wight (although many such redirects do exist and are mostly harmless).

Page names that only differ by capitalization

It is acceptable to create two articles (on different topics) with titles that differ only in capitalization. If this arises, place a hatnote at the top of each page, linking each to a dedicated disambiguation page or to the other article. It is also acceptable to use names that are differentiated in other ways; which approach should be taken may vary from case to case, balancing such considerations as the risk of confusion in using one set of names against the departure from brevity and common usage in using the other.

Organisms

See: Wikipedia:Manual of Style#Animals, plants, and other organisms, and the naming conventions for fauna and flora, and the WikiProject Birds naming guidelines

Common names of species generally do not have each word capitalized, except where proper nouns appear (maple tree, zebra, but Przewalski's horse). An exception is common names of bird species, which like the names of dog breeds (e.g. Scottish Terrier), have been argued as being proper nouns by many specialist sources including the IOC which maintains a standard list of the bird names of the world in response to a formerly chaotic situation of widespread regional variation and ambiguity. WP:WikiProject Birds recommends using this standard which (generally) capitalizes each word but with more complex rules for hyphenated group names. Where more than one capitalization is possible, redirects should be created from the alternative form(s). This is not followed for group names like egret, hawk and so on just as in animal breeds (e.g. terrier). For details, see the topic-specific pages listed above.

Capitalization of expressions borrowed from other languages

For French, see for instance Wikipedia:Manual of Style (France & French-related)#Works of art. In many foreign languages the capitalization rules are different from those in English. The situation is further complicated by loan words, for example a French expression can be adopted in English (so that you'll find it in English dictionaries), but with a different capitalization:

• Art Nouveau is how the name of a certain art movement is usually written in English;
• art nouveau is how it is written in French.

If the article is about a work in a foreign language (such as a book or other written work, movie, album, or song), using the capitalization found in most English language reliable sources is recommended. Otherwise, a two-step approach is advised:

• Check whether or not a French expression has been adopted in English as a loan word: if it is, follow the usual English capitalization rules, as explained in other parts of this page.
• If the French expression is untranslated (not a loan word), follow French capitalization practice. There are some rules for French (usually: capitalize nouns in the expression that taken as a whole is a proper name, and in addition to that always capitalize the first word of the expression even if it is not a noun), but anyhow for many works of art the capitalization practice can be derived from the original publication, e.g. the capitalization of the title of a French novel can usually be derived from how it was published.

For Spanish, German, and any language usually written in the Latin alphabet the same (or something similar) would apply.

Examples

• Multiword articles: Practical joke, Particle physics, Russian constitutional crisis of 1993
• Proper names: North America, William Shakespeare, International Phonetic Association
• Proper names within article titles: History of the Soviet Union (1985–1991), Politics of the United States
• Titles of books and other works: A New Kind of Science, Ghost in the Shell, Oliver Twist

• Help:Renaming (moving) a page
• Wikipedia:Manual of Style/Capital letters
• Wikipedia:Manual of Style/Trademarks
• Wikipedia:WikiProject Albums (capital letters)