If it were my original design and someone else was copying it with a minor change and it was costing me money, then it would be an issue. But, Al Toth's Elk Hair Caddis was tied a specific way, if you add or delete a part of the fly, it is no longer Al Toth, It's Joe Blow's Elk Hair Caddis. Copyrighting Is not that expensive, especially if you did several at the same time.