All information in Wikipedia articles should be verified by citations to reliable sources. Our preferred method of citation is using the "cite.php" form of inline citations, using the <ref></ref> elements. Using this method, each time a particular source is mined for information (don't copy word-for-word!), a footnote is placed in the text ("inline"), that takes one to the detail of the source when clicked, set forth in a references section after the text of the article.
In brief, anywhere you want a footnote to appear in a piece of text, you place an opening <ref> tag followed by the text of the citation which you want to appear at the bottom of the article, and close with a </ref> tag. Note the closing slash ("/"). For multiple use of a single reference, the opening ref tag is given a name, like so: <ref name="name"> followed by the citation text and a closing </ref> tag. Each time you want to use that footnote again, you simply use the first element with a slash, like so: <ref name="name" />.
In order for these references to appear, you must tell the software where to display them, using either the code <references/> or, most commonly, the template, ((Reflist)) which can be modified to display the references in columns using ((Reflist|colwidth=30em)). Per our style guidelines, the references should be displayed in a separate section denominated "References" located after the body of the article.