French Morocco With Tetouan Postmark

Here is French Morocco Scott 18 with a Tetouan postmark.

Tetouan (or Tetuan) was located in Spanish Morocco at the time. According to The Stamp Atlas by Wellsted, et al., France did not have a post office in Tetouan (Germany and Britain did have POs there).

Any clues as to how a Tetouan postmark ended up on a French Morocco (more correctly, French Offices in Morocco) stamp?

Thanks,

Robert

P.S. The cancel gives the lady a nice droopy mustache.

As you can see, the stamp bears the overprint "centimos" that is Spanish and not French. It is a French postal agency stamp from before the existence of the protectorate.

Up to 1900, Spain remained the predominant power in Morocco. A treaty of 1900 recognised France's intervention. The borders, however, were not set before 1902. Already in the late 1900s and before the 1912 partition into the Spanish and French Protectorates (and the Tangier International Zone), the major European powers had postal agencies throughout Morocco. Up to 1902, the French postal agencies used French stamps overprinted in Spanish currency. From 1902 until 1912 they used overprinted stamps inscribed "MAROC."