Weapon Finesse [General]
Prerequisite: Base attack bonus +1.
Benefit: With a light weapon, rapier, whip, or spiked chain made for a creature of your size category, you may use your Dexterity modifier instead of your Strength modifier on attack rolls. If you carry a shield, its armor check penalty applies to your attack rolls.
Special: A fighter may select Weapon Finesse as one of his fighter bonus feats.
Natural weapons are always considered light weapons.
Source: SRD 3.5 Feats