An assignment patch is a patch or badge worn on a uniform indicating the individual's posting.
The Federation's 23rd century Starfleet uniforms continued the tradition of assignment patches. On these uniforms, the patches were smaller than their 22nd century Earth counterparts and located over the left breast. (TOS: "The Cage", et al) This lasted until approximately 2278 when the assignment patch was replaced by an emblem, which, by the 24th century, was replaced by a combadge. The emblem used for both was the USS Enterprise's mission patch. (TNG: "Cause and Effect", "Encounter at Farpoint")
- The assignment patch was still in use by Starfleet in 2271, as evidenced in Star Trek: The Motion Picture, but no longer used by 2278, as seen aboard the USS Bozeman crew in "Cause and Effect".