Sanction?

So I got to Chief Serpent Sergeant. Then I talked to the battle mage and he gave me a sanction (effect) that lasts 2 hours but IDK what it even does. I talked to him again and he just rebuffed me with it. His description is vague as heck, so that's not helping either.

If you have gear that you bought with GC seals, it may have a Sanction bonus on it. The buff activates the gear bonus.

Oh I see now. In the place were it normally says "Set bonus: Order of the Twin Adder Uniform 2 Equiped" it says "Sanction" on the lvl 44 (Chief Rank) weapons. Makes sense now. Thanks.