Hello, this isn't about a bug, just a general support question. Is "WinSCP" trademarked?
No, it's not. Why do you ask?
Well, it is! According to international law you get a trademark not by registering (which helps in legal cases), but by bringing an item into the public, distributing and selling it etc. That's why there are trademarks (this case) and 'registered' trademarks. So if Mr. Prikryl invented that name (don't know) it is now his product and he has all rights to the trademark. If someone else now 'registers' it at the patent office that registering is worthless, as WinSCP had been used publicly before. The newer trademark can be fight against easily and will be deleted quickly.
Another internationally valid law protects businesses from copying and stealing other businesses ideas/names/products (don't know the english name, sorry). That already is enough to prevent other companies to ever come up with a product (here software) that is called WinSCP. No need to register it, it is protected already!