TRAIT - Ranged Trip
This weapon can be used to Trip with the skill at a distance up to the weapon's first range increment. The skill check takes a -2 circumstance penalty. You can add the weapon's item bonus to attack rolls as a bonus to the check. As with using a melee weapon to trip, a ranged trip doesn't deal any damage when used to Trip. This trait usually only appears on a thrown weapon.
Source: Bestiary pg. 85