Keycode tag - Keyprof Luke

Today I went to Interclassics at the MECC in Maastricht. At this event I visited a carkey specialist to get some spare keys created. I also brought my XJS sparekey set with me as I wanted to have something checked. The keyring has one small iron tag with a keycode on it. And I was curious to know if it belonged to one of the keys. And if so, which one. He had it checked and it belongs to the ignition key. Nice to have this Original tag with the keys as well.