Greater Weapon Focus [General]
Choose one type of weapon for which you have already selected Weapon Focus. You can also choose unarmed strike or grapple as your weapon for purposes of this feat.
Prerequisites: Proficiency with selected weapon, Weapon Focus with selected weapon, fighter level 8th.
Benefit: 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 (see below).
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.
Source: SRD 3.5 Feats