PDMU are the initial letters for Pentathlón Deportivo Militarizado Universitario (Universitary Militarized Sports Pentathlon), a civic autonomous youth organization born in México in 1938 that pursues "the greatness of the homeland" by means of an integral formative process of Mexican boys and girls, encircled by the motto "Patria, honor y fuerza" ('Homeland, honour and strength').
Despite its Mexican-patriotic spirit, PDMU has presence out of México, among Mexican migrant communities in USA and Canada.
Further information in this Spanish_Wikipedia_article.