Heavy Weapons with [HEAVY] in their profile are known as Heavy weapons. Each time an attack is made with such a weapon, if the attacking model’s unit Remained Stationary this turn, add 1 to that attack’s Hit roll.
Precision Weapons with [PRECISION] in their profile are known as Precision weapons. Each time an attack made with such a weapon successfully wounds an Attached unit, if a Character model in that unit is visible to the attacking model, the attacking model’s player can choose to have that attack allocated to that Character model instead of following the normal attack sequence.