What counts as a "status effect" and what counts as a "buff/debuff"

Fr example, Opportune strike has a CD reduction of 2 turns if hitting a target suffering from "negative status effects". Some things such as Expose don't count for this, even though it is shown in red above the character.
The same goes for "Exploit Weakness", which does an extra 25% for "negative status effect"s.

Does anyone have a list of buffs and debuffs and how the different mechanics interact?