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")
After having traveled back in time to 1986 from 2286, Pavel Chekov's ID card was seized by the US Navy and read aloud by an FBI Agent. The agent did not believe the information on the card, including the fact that Chekov represented Starfleet and the United Federation of Planets. (Star Trek IV: The Voyage Home)