D. Gabrielle was a 23rd century Starfleet commander assigned to the Starfleet Academy's Starfleet Training Command. Gabrielle served as instructor for Inter-stellar Ethnology.
In 2285, Gabrielle was listed on a directory placard found on the 2nd level of Starfleet Training Command. This commander taught the course in room 208. (Star Trek II: The Wrath of Khan)
The placard mentioning D. Gabrielle was sold on It's A Wrap! sale and auction for US$31.99. [1]