A. Noyer 1924 Olympic Postcards
 

Postcards in this set normally have AN and a number on the front of the card.
Occasionally you encounter a card that has neither the AN or number.
I am hoping a postcard or Olympic specialist on this forum can explain the existence of the cards without the AN and number. Are they errors or possibly created at a later date?
Any information would be greatly appreciated.
Thank you in advance.