The FFF has a code of ethics that many have never read.
The following is a shortened version suitable to be carried by the angler:
1.Fly anglers understand and obey laws and regulations associated with the fishery.
2.Fly anglers believe fly fishing is a privilege and a responsibility.
3.Fly anglers conserve fisheries by limiting their catch.
4.Fly anglers do not judge fellow anglers and treat them as they would expect to be treated.
5.Fly anglers respect the waters occupied by other anglers so that fish are not disturbed
6.When fishing from a watercraft, fly anglers do not crowd other anglers or craft or unnecessarily disturb the water.
7.Fly anglers respect other angling methods and promote this Code of Angling Ethics to all anglers.
Via: Aroostook flyers and tyers LINK