Alternative terms
Though one user proposes protosequel as it was more a correct term  , the main meaning of the proto- prefix is first. Thus, the clearer meaning of protosequel would be first sequel (i. e. the protosequel of Star Wars might be The Empire strikes back, while its prequels are The Phantom Menace, Attack of the Clones and Revenge of the Siths). the last versions of this article presented the  protosecuela as a Spanish term. While neither prequela, presecuela nor protosecuela are listed in Real Academia's dictionaries, precuela is far more frequently used than the proposed alternatives, as can be found by a simple google search, or by searching it in the Real Academia Corpus de Referencia del Español Actual which presents two instances of precuela and one of precuelas, while there are none of the alternative proposals.