informal situations typically only the first one is used, although both are needed for legal purposes. A child's first surname will usually be their father's first surname, while the child's second surname will usually be their mother's first surname. For example, if José García Torres and María Acosta Gómez had a child named Pablo, then his full name would be Pablo García Acosta. One family member's relationship to another can often be identified by the various combinations and permutations of surnames. In some instances, when an individual's first surname is very common, such as for example in José Luis Rodríguez Zapatero, the second surname tends to gain preeminence over the first one in informal use. Rodriguez Zapatero, therefore is more often called just Zapatero and almost never Rodriguez only; in other cases, such as in writer Mario Vargas Llosa, a person becomes usually called by both surnames. This changes from person to person and stems merely from habit. In Spain, feminist activism pushed for a law approved in 1999 that allows an adult to change the order of his/her family names, and parents can also change the order of their children's family names if they (and the child, if over 12) agree, although this order must be the same for all their children. In Spain, especially Catalonia, the paternal and maternal surnames are often combined using the conjunction y ("and" in Spanish) or i ("and" in Catalan), see for example the economist Xavier Sala-i-Martin or painter Salvador Dalí i Domènech. In Spain, a woman does not generally change her legal surname when she marries. In some Spanish-speaking countries in Latin America, a woman may, on her marriage, drop her mother's surname and add her husband's surname to her father's surname using the preposition de ("of"), del ("of the", when the following word is masculine) or de la ("of the", when the following word is feminine). For example, if "Clara Reyes Alba" were to marry "Alberto Gómez Rodríguez", the wife could use "Clara Reyes de Gómez" as her name (or "Clara Reyes Gómez", or, rarely, "Clara Gómez Reyes". She can be addressed as Sra. de Gómez corresponding to "Mrs Gómez"). Feminist activists have criticized this custom as they consider it sexist. In some countries, this form may be mainly social and not an official name change, i.e. her name would still legally be her birth name. This custom, begun in medieval