Knowledge (arcana) covers ancient mysteries, magic traditions, arcane symbols, constructs, dragons, and magical beasts.

Knowledge (arcana) task DC
Identify auras while using detect magic 15 + spell level
Identify a spell effect that is in place 20 + spell level
Identify materials manufactured by magic 20 + spell level
Identify a spell that just targeted you 25 + spell level
Identify the spell cast using a specific material component 20
Identify a spell effect that is in place 20 + spell level
Identify a construct creature's abilities and weaknesses 10 + monster's CR
Identify a dragon creature's abilities and weaknesses 10 + monster's CR
Identify a magical beast creature's abilities and weaknesses 10 + monster's CR