"TK-421, why aren’t you at your post?" This stormtrooper whose uniform Luke Skywalker steals was originally designated "THX 1138" in the script and is referred to as such in the novelization of the movie.
"THX/1138" appears on one of the monitors in the Death Star control room.
Luke Skywalker rescues Princess Leia from cell block 1138.
Transformers: Generation 1 is available on Netflix Instant. In 1984, we didn’t know there would be a need to distinguish one generation of transforming robots from another, so we just called them Transformers.