Hi, there is a line in Battlefleet: Koronus for the "Shadowhunter" Eldar craftworld raider:
"
Small and Agile:
Due to their small size and phenomenal manoeuvrability, Shadowhunters are capable of attacking and
destroying torpedoes and attack craft. A Shadowhunter ignores penalties for firing on such targets."
I have not found rules for shooting at attack craft / Torpedoes anywhere else, but this entry suggestst that there are ("ignores usual penalties"). If there are rules for this could someone point out where they are written?