User blog comment:Saratje/NEW Dragonborn content/@comment-3225933-20121127140851/@comment-160529-20121127160929

the exception does not prove the rule.

lets look at mass effect, halo, gears of war, and resistence fall of man. . . yup, their supplemental books and comics are all considered fully canon.

with the occasional exception that is explicitly said to be non-canon (or metafictional in at least one instance).

rule of thumb, unless stated to be not canon, it is canon.