Need Insight on listing of race on death records

This question is from another genealogy site and I'm hoping someone can help this gentleman. The records are from Guanajuato, Mx -sorry. This is a copy & paste of his question.*****Hi everyone. I’m hoping some of you might be able to give me some insight into the listing of race on death records in Guanajuato in 1913 and 1914. I have recently found death certificates for two relatives - a great uncle and a great-great aunt, both of which listed race. They are both listed as Indigena con negra (Indigenous with Black). My initial understanding was that, at least in church records, after 1827 race was no longer indicated unless provided by the family. This is a civil registration and looking through the other records in the database, they all seem to list a race. All are listed as ______ con _______. I can’t find any pattern to how they are listed, such as x race is always listed first, y race is always listed before z, etc. I’ve also noticed in some records a race may be listed twice, such as negra con negra. It would seem to me that it is indicating parental lines, but I can’t find any online source explaining this. I would greatly appreciate any insight anyone might have on how this was recorded or should be interpreted.