Ah, sorry! I missunderstood you, I thought you meant the Knight of the Cross were in under a different name, and that made me a bit confused that I'd missed it :p
The denarians are probably in under "The Order of the Blackened Denarius" or possibly "The Knights of...", these names did probably have no meaning whatsoever to Harry last time he actually read through the accords properly. (if he ever did...)