Those works of the Exalted game line that are considered "official," and are usually the bits referred to by other books. Canon is useful when it provides a yardstick and common point of reference for the players and writers. It is less than useful when it constrains the imagination and stops you from having fun.
Exalted players and storytellers are encouraged to break canon with gleeful abandon when it suits their fancy.
From a Wikipedia entry... "In the context of fiction, the canon of a fictional universe comprises those novels, stories, films, etc. that are considered to be genuine, and those events, characters, settings, etc. that are considered to have inarguable existence within the fictional universe. Usually items that are considered canon come from the original source of the fictional universe while non-canon material comes from adaptations or unofficial items..."
From a less relevant entry from Iolani School's site... "a body of writings considered authentic (eg, the books of the Bible, or all the works by Shakespeare). Now the term is used to mean the literary works considered worthy to be studied in college and included in anthologies. The concept has stirred controversy over the way canons are formed, and whether factors like gender and ethnicity affect inclusion," since maybe only Shataina has ever "studied" Exalted.
- Of course, the problem with breaking canon is that you may wind up making books that have not yet been published, that you would otherwise love to use, impossible to use in your chronicle without considerable adaptation. Then again, there are some books that have come out (Kingdom of Halta comes to mind--actually, most of the "location books" probably qualify) that have that problem even if you haven't broken canon, because they establish canon where there wasn't any before. --MF
- Added some actual definitions I googled up. --UncleChu