“Don't Tread on Me” was issued to rock radio from Metallica's 1991 album, commonly called The Black Album, without a commercial single release.
The song takes its title from the “Don't Tread on Me” motto associated with the Gadsden flag, and its lyrics use patriotic imagery. It appears as a standard album track rather than one of the five commercial singles released to promote the record.
Those commercial singles were “Enter Sandman,” “The Unforgiven,” “Nothing Else Matters,” “Wherever I May Roam,” and “Sad but True.” Each played a different role in presenting the album's range, from heavy riffs to ballad-like dynamics and atmospheric arrangements.
A radio promotion and a commercial single are not identical. A label can service a song to radio stations without issuing it as a retail single, so “Don't Tread on Me” should not be counted among the album's five commercial singles.