By Zak Muscovitch.
It happens. A lawyer sends a C&D letter, or serves a UDRP that relies on a "Registered Trademark". It shows up in the USPTO database, but it may not really be a trademark. How is that possible? When the "trademark" is registered on the "Supplemental Register".
The
United States Trademark Act provides
for the registration of trademarks on either the "Principal" or "
Source