Spanish Marine Province of Costa Firme (Coro): presumably used between 1815 and 1819, is refers by Mr. Jaume Olle in his "Electronical Bulletin of Vexillology from Catalonia", Part: Historical flags / Venezuela - Reus, Spain-Catalonia 1999. Until now, in Venezuela and Spain does not seem exist any specialized registry that guarantees its existence.
Own work using: https://www.fotw.info/flags/ve-hist2.html
Salvadoroff