A pair of fabric strips featured on the costume trousers of Starfleet uniforms in Star Trek feature films - these are the Engineering gold variety as Scotty wore. They were only present on Engineering Officers wearing the 'monster maroon' costumes. The items are folded over and stitched sealed; meant to be sewn onto the outside seam of trousers to indicate the wearer to be a member of the engineering division. They retain threads from removal.
A screen-cap from Star Trek VI: The Undiscovered Country shows Scotty wearing a set of these strips.
More from Star Trek VI: The Undiscovered Country (1991)