These are combos of numbers and letters that are given by a casino's affiliate sites to show that a user has satisfied reward terms. Users enter them on the casino site to claim bonus bets and spins. This means that they can get to play some casino titles without using their own money.
Spain is a lovely country in Southern Europe that borders France and Portugal. Barcelona and Madrid, the two major cities in Spain, are some of the most visited cities in the world. Thanks to the open culture, it's not hard to find a casino here, and most often one can find many online mobile gambling offers.