Pair of original "Please Return to Tiffany & Co." engraved cufflinks, which is now a famous jewelry collection, was first introduced in 1966 on key tags. Each of these key tags was given a unique registration number. The idea was that if the owner lost their keys, a finder could drop them in a mailbox, and the key tag would be returned to Tiffany's flagship store on Fifth Avenue in New York. The staff could then use the registration number to reunite the keys with their rightful owner.