Hey guys... I think there is some misinformation going on here about trademark, patents, and copyright. There are lawyers that make good bucks in these fields - so it's not something that is easy to simplify in law.
Having said that, I doubt that someone could put a patent on a fly unless it was using some very unique and new materials. Or perhaps some new and unique tool to tie flies could be patented.
Trademarks are interesting and I doubt very much that it would stop anyone from making any claims about a fly's recipe. I could create a fly, give it a name and then register a trademark for that name - you go out and make the same fly and just give it another name. Check out the Wikipedia entry on trademark
for a better understanding of what it is.
But as far as copyright, a "recipe," like the rules of a game, are not copyright as far as I know. It is my belief, and a lawyer can correct me if I'm wrong (but I've had a lawyer already explain this to me) that a recipe for anything can be written anywhere.
However, the instructions for how the recipe goes together.. the "cooking" so to speak, IS copyright and you can't just use someone else's work to explain the process.
It IS unfortunate that there are some who don't do the "right" thing in giving others credit - but it happens in life.
One thing that many fly tiers have done, when they make changes to an existing fly, they call it by the original name but add the word "Variant" after. I think that's pretty cool. "H & L Variant" comes to mind.