Making Radio "Supplementary channel" codes permanent.

[Roomba]

Personally, I think robochat sees more use that secchat so I'd prefer it staying the same, although I'll agree the codes are fairly arbitrary and anything works if there's some level of justification for it. I think :h should still default to whichever private channel your job gets access to, though.

As for the emergency channel, I dunno how useful it'd be. Isn't that what the 'message dept/person' option on the PDA is for? It seems if people aren't paying attention to chat, they're not going to pay attention regardless of what colour it is.