Effects of weapons % modifier on damage

How does the weapon damage modifier (like 15^50, 20%hexed 15%stanced etc) apply on final damage?
I mean, the damage boost is calculated on:
-base weapon damage (if you have the requirements) ?
-base weapon damage + Weapon mastery modifier?
-final damage (after AL check)?
-final damage+Attack skills damage bonus?
-or....?

This is just a wild guess:

-base weapon damage (if you have the requirements)

Just trying to tease those gurus who can't resist to correct me with their better knowledge.

final damage+Attack skills damage bonus i think.

I think the 15^whatever is a global enhancement.

Ive read its just base weopon damage.

oh wait, the attack buffs always go last.

my bad.