904.04(c) Package Inserts
If material inserted in a package with the goods is merely advertising material, then it is not acceptable as a specimen of use on or in connection with the goods. Material that is only advertising does not necessarily cease to be advertising because it is placed inside a package.
Package inserts such as invoices, announcements, order forms, bills of lading, leaflets, brochures, printed advertising material, circulars, press releases, and the like are not acceptable specimens to show use on goods. See In re Bright of Am., Inc., 205 USPQ 63 (TTAB 1979).