/s <msg system>, which sends a message to anyone in your system(and your current mode), would be cool too.
/f <msg faction>, which sends a message to any member of your faction (in your current mode).
/p <msg PowerPlay>, which can broadcast to all allies in your power (in your current mode).
System, group, faction, and PowerPlay chat might become spammed, so individual CMDRs need to the option to opt in or out of receiving them.
CMDR Cosmic Spacehead
....could additionally have
/g <msg group>
For group-wide announcements, similar to the server announcements we have now.
Spammed? Really? I mean it's pretty damned amazing for me to see open chat from other players when I'm gaming. Tell me what time I should be on and where in the sandbox I need to be in order to see Commanders spamming each other in chat. The only spam I see usually is the NPCs taunting me to stupidity with "...all that tasty cargo...". It's especially amusing when I'm hauling biowaste for democracy.
Presumably this would only be available to the creator / owner of the Private Group?
If it can be spammed. It will.
Human nature 101. Lol
Have you ever played any other online game ever?
CMDR Cosmic Spacehead