There are numerous pitfalls that may arise whenever any other party is allowed to use your mark.
Motorcycle Hall of Fame
The mark Motorcycle Hall of Fame is registered with the U.S. Trademark Office for multiple items including jewelry (pewter, bronze, gold plated lapel pins, gold plated bracelets, necklaces, charms, and belt buckles of precious metals). REGISTERED TRADEMARK 2,911,948
The U.S. Trademark Office requires an applicant to provide a description of the goods and services associated with the mark being registered.
While it is not illegal to allow (i.e., license) someone else to use your mark, there are numerous pitfalls that may arise whenever any other party is allowed to use your mark.
Unless you have a nationally recognized, famous mark that could raise significant revenue from licensing other goods and services to use the mark, the best approach is to avoid allowing any other party to use your mark. In any event if you believe the circumstances may merit further consideration, seek advice from an experienced trademark attorney.