The I.D. card of Lieutenant Christine Chapel
In 23rd century Starfleet practice, an identification card was a card carried by Starfleet personnel for identification purposes. The ID card showed a person's service number and name, as well as his or hers assignment and division.
Identification cards could be created aboard Starfleet starships, and they were sometimes necessary to gain access to certain areas, like a ship's shuttlebay. (TAS: "Mudd's Passion")