Quote Originally Posted by Nexxus View Post
Do not forget about exp bonus:

Free Company Buff, food buff, Mercenaries buff (A mission in the Grand Company vault), leading you to an 28% exp increase.

If you are talking about Squadron Battle Manual, I'm pretty sure they don't stack with FC buffs, because it works the same as tier 3 FC buff. If you are talking about something else, I have no idea what you are talking about "GC Vault"