The United States Patent and Trademark Office (USPTO) may be required to refuse registration of a mark on numerous grounds. One reason is there is a Likelihood of Confusion as to the source of the mark.

The USPTO's attorney conducts a search for conflicting marks as part of the official examination of an application to determine if there is a conflict between the mark in the application and a mark that is either registered or pending in the USPTO. This assessment is based on the mark's sound, appearance, meaning, commercial impression, and meaning as well as the goods and services classifications. See below.