Basically, the trademark is already unenforceable. It is in such common use now that Marvel & DC do not have a leg to stand on. Provided you had the money to keep up with all their appeals - the trademark would be overturned and (possibly) the two corporations would have to pay you legal fees (there was a case recently where Mattel was forced to do this for suing someone making parodies of Barbie). Given your reasoning momodot, it is perfectly acceptable for Microsoft to trademark the term "Windows". Believe it or not - Microsoft knows the term is on very shaky ground (as the term "windows" for the GUI was coined before they made the Windows software) and always settles when the company they are suing comes close to the end of a court case (i.e. before the judge is allowed to rule the trademark invalid). Just because someone obtains a trademark does not immediately make it valid. In exactly the same way that obtaining a patent does not make it valid. It simply means that the reviewer did not do their job properly. --EK