The Vest Variant
In the Original Series movie era, some great new characters were added to the crew of the Starship Enterprise. In Star Trek II we were introduced to the character of Saavik, then played by Kirstie Alley. The character was brought back for Star Trek III and IV, then played by Robin Curtis.
With Saavik's return in Star Trek III, we were shown one of the cooler Monster Maroon uniform variations. In early scenes on board the USS Grissom, Lt. Saavik wears a standard maroon uniform. But once on the Genesis Planet she wears the same type of field jacket introduced in Star Trek II, beneath which she wears a leather vest and a long-sleeved white turtleneck in the same style worn with the full maroon uniform. She then wears this costume for the remainder of the film.
Both the vest and shirt have costume tags reading "Robin Curtis". The pants are production made with the red stripe of command.
A vest was first introduced in Wrath of Khan and worn by Kirk (I have the prototype of that vest in my collection). A version was also worn by Scotty in Star Trek IV, V and VI.