Voice, chat radius' and tags.

Any links to the wiki would be great.
I’m asking how you can add a radius on the chatbox and voice.
Oh yeah, don’t forget tags such as (RADIO).
I havn’t looked into this much, and thought it’d be quicker posting here.

[lua]return whatever, true – second return on PlayerCanHearPlayersVoice is for proximity voice chat[/lua]