Hello,
So I have been trying to figure out what this stamp is:

Some things to note:
1) It says "Correos" in the upper right, indicating that it is a stamp.
2) It does not say "Espana" or "Republica Espanola" on it, which is the norm for Spain.
3) It clearly references Barcelona, which is in Spain.
4) On the back it has "Series 6 - LL" in light green and "261198" in blue. Old Spanish stamps have numbers printed on the back.
Scotts says that during the Spanish Civil War (1936-39) cities in Spain issued charity semi-postal stamps. Is this one of those stamps? Or something else?
Thanks for any insights.