On March 9, 1999, Switzerland issued two stamps featuring the cartoon character “Pingu” in the context of postal services. On both stamps parcels were shown wrapped with parcel cord. This was not per se against Swiss postal regulations, but it was not favored either.

Therefore, on December 6, 1999, stamps without parcel cord, but otherwise identical, were issued. A peculiarity is the fact that the new stamps were delivered to postal offices on November 27, 1999, and some of them were sold before the first day of issue on December 6, 1999, since the postal clerks did not necessarily check on the difference when selling and using the stamps.