We have a gripper body with two possible finger sets and, naturally, both have ended up being called the same tool. The drawings can be sorted later; on the bench I need somebody to tell which complete arrangement they have before it goes back on.
Would you mark the fingers, the assembly, or the storage position? Looking for something that survives ordinary workshop behaviour rather than a beautiful scheme nobody follows.
Mark the complete assembly first. A finger label helps identify a loose part, but it does not tell stores whether the adapter and fittings are the intended combination. One assembly identifier on the returned kit gives you something checkable.
Fair. The storage position can support that rather than carry the meaning. If the tray is moved, the label still has to make sense, which is annoyingly obvious once you say it.
Worth putting the assembly ID on the fitment check too. Labels get ignored when a job is rushed; a short check asking which set is fitted catches it before someone starts altering points to suit the wrong fingers.