Spanish Tangier 1937 Set

Does anyone know anything about this set of 1937 Spanish Tangier stamps? ebay dealers list them as charity stamps with an EDIFIL number. However, they are not listed by Scott in either of the Spain listings or the Spanish Morocco listings. Any background information would be appreciated.

These are fundraising labels, and were not good for postage. They were sold to raise money for orphaned children.

These were part of a long run of issues sold to support an orphanage for children of postal workers between 1921 and the late 1930s. While for the most part not officially authorized for postage, they were often accepted as such by postal workers supportive of the cause and sometimes included on envelopes by postal patrons hoping to ensure timely service. I would also suspect many were absorbed by the philatelic market.

Thank you to all for your responses -- just the information that I was looking for.

Great info Roberto. Which catalog is that?