A trademark is a word, name, symbol or device which is used in trade with goods to indicate the source of the goods and to distinguish them from the goods of others. A servicemark is the same as a trademark except that it identifies and distinguishes the source of a service rather than a product. The terms "trademark" and "mark" are commonly used to refer to both trademarks and servicemarks. Nobody can get trademark ownership of a generic term.
Trademark rights may be used to prevent others from using a confusingly similar mark, but not to prevent others from making the same goods or from selling the same goods or services under a clearly different mark. The trademark is used to guarantee that people aren't confused into believing that the product they're buying was made or sold by a company who had nothing to do with it. For people who like to know that things are authentic, trademarks serve as a way of avoiding being ripped off.
The system of trademarks is easily exploited by those praying on popular items whose developers do not officially register their trademark. Domain Name registration for internet, open source and other collaborations is prone to such activity. Claiming prior art through the legal enforcement can be costly and time-consuming.
- US Trademark Law: Rules of Practice & Federal Statutes
- Trademark Law Treaty Implementation Act
- TM Amendments Act of 1999 - .pdf file
- Legal Information Institute: Law about trademark - an overview, links to code
- Trademark blog by Martin Schwimmer