Needs review
Source: Player's Handbook

Description: You are especially good at using a weapon you have weapon focus with.

Prerequisites: Weapon Focus, Base Attack Bonus +8, Weapon Proficiency

Required for: Epic Weapon Focus, Greater Weapon Specialization

You gain a +1 bonus on all attack rolls you make using the selected weapon. This bonus stacks with other bonuses on attack rolls, including the one from Weapon Focus.

Special

You can gain Greater Weapon Focus multiple times. Its effects do not stack. Each time you take the feat, it applies to a new type of weapon. A fighter must have Greater Weapon Focus with a given weapon to gain the Greater Weapon Specialization feat for that weapon. A fighter may select Greater Weapon Focus as one of his fighter bonus feats.