Canon

\'ka-nen\ (n.) &mdash; a sanctioned or accepted group or body of related works
 * ''For other uses, see Canon

As Star Trek grew in both size and popularity in the 1980s, fans were faced with the problem of how to treat the ever-growing collection of episodes, movies, novels, comics, technical manuals, and more.

The Star Trek canon is generally defined as all live-action television series and feature films released by Paramount. The various "official" references (such as the Star Trek Encyclopedia or the Star Trek Chronology) may be used as a guide to canon information, but are not canon in and of themselves. The animated Star Trek cartoon series (aired 1973-1974), the various novels, and other creative works are not considered canon.

The definition of Star Trek canon may vary for different fans, and therefore for a reference source like Memory Alpha, the question may become especially difficult.

In those cases, the term fanon is used to refer to "fan canon" (of which the term is a portmanteau). It applies to certain "facts" that may have been accepted as a truth by a large number of fans, and thus either replaces an established canonical fact in the minds of those fans, or fills a plot-hole.

Fanon can also take the form of personal beliefs held by individuals. In this case, an individual may create an expansive backstory, possibly a fan fiction, which they accept as "true." These have less standing than even the fanon mentioned above.