Definition of canons:
(n) :
A group of literary works that are generally accepted as representing a field.
(n) :
A generally accepted principle; a rule.
(n) :
The works of a writer that have been accepted as authentic.
(n) :
(chiefly fandom slang, uncountable) Those sources, especially including literary works, which are considered part of the main continuity regarding a given fictional universe; (metonymic) these sources' content.
(n) :
A religious law or body of law decreed by the church.
(n) :
A formally codified set of criteria deemed mandatory for a particular artistic style of figurative art.