He added more data as nickname of Francisco Paco: the origin seems to be Church, next to the name of the Holy order, they used to write Pa. Co. (by Pater Comunitatis), which started to use as hipocorístico. See Pepe. It is also an acronym for the paste cocaine base. And in slang is called so the WAD of bills, to the package or bulk; Italian pacco. See gang, tocomocho.