Unfortunately Halo is not very friendly when it comes to things like that. Really annoying.
As far as im aware, the console is completely separate from the chat function and does not support its own chat. I think some modders were working on something like this in a multi function program for Custom Edition and had said they were able to do it for PC too, but that was last year and have not seen any update on it. Possibly hit a brick wall after the 1.08 update.
This is why us race clans use "3rd party?" programs to auto display rules.