From the episode “Measure Of A Man”, this is Data's full name as shown by the Enterprise computer (to Cmdr. Riker): Lt. Cmdr. NFN NMI Data.

Spelled out, this becomes:

Lieutenant Commander "No First Name" "No Middle Initial" Data.

Originally, Data was to be the Chief Science Officer of the Enterprise, much like Spock was on the original series, and wear a blue tunic. However, the blue tunic clashed with his android make-up and the idea was scrapped. Data was reassigned as Chief Operations Officer of the Enterprise and sported a gold tunic for all seven seasons, except for the two-part episode “Chain of Command,” in which he is promoted to First Officer and wears a red tunic.

Bob Justman was taken by Sean Young’s role as the replicant Rachel in Blade Runner, and suggested a similar type of female character as a science officer who might be part Vulcan, related to Spock, or even Kirk.

The character of Tasha Yar was originally to be a Latina named Macha Hernandez, inspired by the tough female marine Vasquez in the movie “Aliens” (1986). In fact, Jeanette Goldstein, who played Vasquez, auditioned for the character, and later played the Enterprise-B science officer in “Star Trek: Generations.”