The original Starfleet deltas were patches sewn onto the uniforms. The original "Star Trek" series, recall, featured color-coded uniforms that indicated the department in which they worked.

Star Trek’s Starfleet insignia, often referred to as the "delta," is one of the most recognizable images in science fiction. Featuring prominently on the uniforms of Starfleet officers ...

In Star Trek lore, few symbols are as iconic ... Justman addressed the use of the unfamiliar insignia in the Exeter's crew uniforms in "The Omega Glory," emphasizing that all Starfleet personnel ...