Spanish naming customs
Both surnames are sometimes used when the first surname is very common (e.g., Federico García Lorca, Pablo Ruiz Picasso or José Luis Rodríguez Zapatero) to get a more customized name. In these cases, it is even common to use only the second surname, as in "Lorca", "Picasso" or "Zapatero". This does not affect alphabetization: "Lorca", the Spanish poet, must be alphabetized in an index under "García Lorca" and not "Lorca".