OFFICIAL F.I.P.S.e.d. RULES OF INTERNATIONAL “FOR NATIONS” COMPETITIONS “TROUT AREA”
– Butterfly – Allowed
– After a fish has been rescued with the “butterfly” technique or has been landed and put back into the water with the aid of the landing net itself, it is subsequently unhooked using the Releaser. The unhooking operation with the Releaser must be done in water and not in the air.
– Any catches self-released near the landing net without ending up inside it, cannot be considered valid since the fishing action must be considered concluded; subsequent catching of that fish using the landing net is not allowed;
For more informations look for official document.