The registered trademark symbol (®) is a symbol that provides notice that the preceding word or symbol is a trademark or service mark that has been registered with a national trademark office. A trademark is a symbol, word, or words legally registered or established by use as representing a company or product.. Notwithstanding the symbol doesn't meet the threshold of originality to be protected by copyright because it consists only in a capital letter rounded by a simple geometric shape, in some countries it is against the law to use the registered trademark symbol for a mark that is not officially registered in any country.