###  (the +c 'common' flag)
   sometimes a lot of people use irc from the same account -- for
   example, a telnet site.  in that case, a whole bunch of people
   will have the same user@host.  so they can't use a traditional
   user record because they will appear to all be the same person.
  
   in this case, you create a user record for the account, and mark
   it +c, or "common access".  that means that it shouldn't be used
   as a definitive address.  when someone introduces herself to the
   bot (ie, by /msg'ing "hello"), if she matches as a +c user, she
   will be given a new user record which identifies her BY NICKNAME.

   obviously people with that kind of user record shouldn't be given
   much special access, since when they change nicknames, the bot
   will identify them as someone else.
