In general, trademark rights go to the first user of a mark. There’s no fee or filing system required to establish trademark rights. Rather, these rights are created and last so long as an owner continues to use the mark. Practitioners sometimes call trademarks resulting from use common-law trademarks.

At common law, use means selling a product or service with the mark attached. However, use doesn’t give an owner trademark rights everywhere. Using the mark in commerce in this way gives an...