Genres are types, classes, or kinds of literature, art, music, etc., but what do you call the marks, signs, or formulas that identify a genre?
The literary-critical term is "conventions," which everyday speech might describe as
Oxford English Dictionary
9a. General agreement or consent, deliberate or implicit, as constituting the origin and foundation of any custom, institution, opinion, etc., or as embodied in any accepted usage, standard of behaviour, method of artistic treatment, or the like.
9b. In a bad sense: Accepted usage become artificial and formal, and felt to be repressive of the natural in conduct or art; conventionalism.
10a. A rule or practice based upon general consent, or accepted and upheld by society at large; an arbitrary rule or practice recognised as valid in any particular art or study; a conventionalism.
Definitions of convention on the Web:
Not rules but expectations (which can be purposefully frustrated)
One way we practice judgment is to measure our reactions to expectations.
Does a specimen or example fall short of expectations, or take us further?
If further, was that a good change or a bad change?
Knowledge of genres = yardsticks, standards of measurement
Standards do not equal rules. Standards can be bent, raised, lowered, varied to need.
adjective form: "conventional"
Definitions of conventional on the Web: