Wikipedia:Naming conventions (capitalization)

Convention: Unless the term you wish to create a page for is a proper noun, do not capitalize second and subsequent words.

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. In future versions of the Wiki software, this may occur with all words; but for now these letters are case-sensitive so pay close attention to the conventions. For multiword page titles, one should leave the second and subsequent words in lowercase unless the title phrase would always occur capitalized, even in the middle of a sentence (for example, a book title). If we capitalize too many words within a page title, then whenever we want to link (quickly and easily) to that page, we must capitalize it in our running text.

But this results in grammatically incorrect sentences, which is jarring. For example, I would much rather write "Good on potato chips is clam dip" (which points to Clam_dip; see above) than "Good on potato chips is Clam Dip" which makes it look like I'm talking about the God of Clam Dip, or something. Another example: philosophical doctrines are usually lower case: direct realism. If a page is entitled Direct Realism[?], then in a simple link to that page, the words "Direct Realism" would have to be capitalized. This would be unusual, and possibly irritating to the reader.

Most names of doctrines shouldn't be capitalized. Most jargon should not be capitalized. Most long phrases (for example, the most remarkable formula in the world) shouldn't contain capitalized words, unless correct spelling requires it (as in Ich bin ein Berliner).

Animals

The agreed policy is that all words in a species' official common name should be capitalised, other than those following a hyphen if they refer to a part of the animal: "Bald Eagle", "Red-necked Phalarope", "Wilson's Storm-Petrel". There must always be a lower case redirect to the main article. See Wikipedia:Naming conventions (fauna).