Two scenarios best explain the reason you will want to tag your cookware. The first being simple identification at cooking events, large gatherings and competition cook-offs. The second reason is to record research information, and attach it to that piece of cookware, once you start collecting cast iron.
If you haven’t already developed a code system for your tags you will quickly see the need. A good system will also allow you to rematch tops[lids] and bottoms, that may get mixed up at gatherings, during clean up, or while in storage.