A more thorough explanation:

An Assistant Commissioner for Trademarks is a person who assists the Commissioner for Trademarks in managing the trademarks section of the U.S. Patent and Trademark Office. The Commissioner for Trademarks is the chief operating officer of this section and is appointed by the Secretary of Commerce.

For example, if the Commissioner for Trademarks is unavailable, the Assistant Commissioner for Trademarks may step in to manage the section's operations. They may also work together to develop policies and procedures for trademark registration and enforcement.

Overall, the Assistant Commissioner for Trademarks plays an important role in ensuring that trademarks are properly registered and protected in the United States.