> The official names of population centers are defined in the INE database. The mapping of other agencies is not binding.

May I see where this statement comes from? The official names for the spanish municipalities comes from https://registroentidadeslocales.mpt.es/REL/, where the NGBE get the names from.

NGBE (Nomenclátor Geográfico Básico de España) can be consulted at https://centrodedescargas.cnig.es/CentroDescargas/nomenclator-geografico-basico-espana and also https://centrodedescargas.cnig.es/CentroDescargas/nomenclator-geografico-municipios-entidades-poblacion (NGMEP) where we will see the name is El Palmar as primary, and Lugar de Don Juan as secondary.

INE (National Statistics Institute) does not define any official name.