From Compendium of Worldly Lore
Needs review
Source: Player's Handbook
Description: Your ranged attacks can ignore the effects of cover or concealment.
Prerequisites: Point Blank Shot, Precise Shot, DEX 19, Base Attack Bonus +11
Required for: Uncanny Accuracy
Your ranged attacks ignore the AC bonus granted to targets by anything less than total cover, and the miss chance granted to targets by anything less than total concealment. Total cover and total concealment provide their normal benefits against your ranged attacks.
In addition, when you shoot or throw ranged weapons at a grappling opponent, you automatically strike at the opponent you have chosen.
Special
A fighter may select Improved Precise Shot as one of his fighter bonus feats.
An 11th-level ranger who has chosen the archery combat style is treated as having Improved Precise Shot, even if he does not have the prerequisites for it, but only when he is wearing light or no armor.
Normal
Without this feat, a character who shoots or throws a ranged weapon at a target involved in a grapple must roll randomly to see which grappling combatant the attack strikes.