So what is the Guardsman version of the custodes I've been trying to remember and can't find it.

A friend of mine and me were talking about the custodies and I remembered that there were some sort of Guardsmen group that were on a very high level compared to the custodies and we're basically the custodians of the guardsman. I don't know much about the lore buts all very interesting. Also the emperor of man is best man.