They are excellent luggage labels, as described by many other posters. With the advantage that no matter where they get lost, the airport finding the case should be able to identify which carrier to return the luggage to. There is a reasonable prospect that the name and number will assist an early reunion.

As I have posted elsewhere on FT, the Tesco barcode label when attached to a bunch of keys works equally efficiently. If found and handed in to the police (or even Tesco!) are very quickly able to establish the owner. In that case I was aware of, the police were round at the robbers house extremely quickly!!