T. Snowdon's name was listed on a personnel assignment log
T. Snowdon was a Starfleet officer in the 24th century.
In the 2360s, this individual served under Captain Leyton aboard the USS Okinawa when Benjamin Sisko was the ship's executive officer.
In 2372, this individual was assigned as a Hygienist, Starfleet Dental. The effective date of this assignment was 49267. This officer was one of over four hundred officers reassigned in a three week period by Leyton. This officer's name was listed in the personnel assignment log that was displayed on a screen in Sisko's temporary office in Starfleet Headquarters. (DS9: "Paradise Lost", okudagram)
The unauthorized reference book The Nitpicker's Guide for Deep Space Nine Trekkers (p. 339) notes that the crew of the Okinawa (apart from Sisko) were named after characters in Joseph Heller's novel Catch-22. Snowden was a radio-gunner in the novel.
According to the ebook The Oppressor's Wrong, his full name is Ishmael Snowden. By contrast, the novel Rough Beasts of Empire depicted Snowden as a woman.