Usage: servergroupclientlist sgid={groupID} [-names]

Displays the IDs of all clients currently residing in the server group 
specified with sgid. If you're using the -names option, the output will 
also contain the last known nickname and the unique identifier of the 
clients.

Example:
   servergroupclientlist sgid=16
   cldbid=7|cldbid=8|cldbid=9|cldbid=11|cldbid=13|cldbid=16|cldbid=18
   error id=0 msg=ok