I've been looking too, including here: (this is a ProZ entry from Peru):
https://www.proz.com/kudoz/spanish-to-english/certificates-d... (However, I can't find anything to do with "LG", but the link mentions "BOL" and "CE" (BOL= Boleta Militar (Military Registry/Paper) & Cédula Militar) and also DOCUMENTO NACIONAL DE IDENTIDAD (DNI).
Again, for what it is worth, but don't see why, I found "Libreta Tributaria (LT)":
LIBRETA TRIBUTARIA, REGISTRO PATRONAL, RUC (11 DIGITOS), RUC (8 DIGITOS), SIN IDENT. FISCAL. N° de Documento(*). BUSCAR. Razón Social(*).
https://apps4.mineco.gob.pe/empleador/registro.htm Stay safe and regards.