We need significant coverage. We need multiple sources that discuss the topic directly and in detail. Not: passing mentions, directory listings, government records, or any old thing that happens to have the topic's name in it.

We need sources that are reliable. Usually this means that the publisher has a reputation for fact checking and the text must be approved by an editor before it is printed. For example: books from reputable publishing houses, mainstream newspapers, or other periodicals. Not: tabloids, discussion boards, fansites, social media, or most blogs.

We need sources that are independent from the subject of the article. Not: books or articles written by the subject (including interviews), articles paid for by the subject, press releases, a Q&A interview where virtually all of the information is just the subject or a spokesperson speaking for themselves.

Readers should be able to rely on what they read and be able to verify claims they read in Wikipedia articles. So, add footnotes to your article citing reliable sources as described.

• This is not a policy or guideline; please defer to such in cases of inconsistency with this page.
• For an explanation of the title of this page, see The answer to life, the universe, and everything, and in particular, the repeating attempts of adding "mostly harmless" at Talk:Earth

• Wikipedia:Don't cite WP42 at AfD
• Wikipedia:Cite WP42 at AfD
• Wikipedia:Everything you need to know: a similar guide in the same style.
• Wikipedia:Common sourcing mistakes (notability)
• Hitchhiker's guide to the galaxy