The arrival roster at Deep Space 9 listing Capt. Sondheim
S. Sondheim was a starship captain in the 24th century. Sondheim was the commander of the USGS Powell.
In 2370, Sondheim was listed on the Deep Space 9 arrival roster. (DS9: "Whispers", production art)
This character was only mentioned in writing.
The graphic was also populated by a number of other in-jokes. He was presumably named after composer Stephen Sondheim.