ANH: "prisoner transfer from cell block 1138"
ESB: "send rogues 10 and 11 to section 38"
ROTJ: i'm told that 1138 appears in the stars at the end battle. but i've never seen it myself.
TPM: 1138 is the number of a battle droid (end battle, droid ship goes critical, and the 1138 droid turns off right in front of jar jar)
AOTC: when Padme falls out of the transport and rolls on the sand she leaves a 1138 in the sand.
and there are a couple of '1138's on clone trooper helmets
commander 1138 is one of the clone troopers that is ordered to turn on the jedi
i'll let Astro carry on asking questions seeing as he's so good at it.