Invite people
Get your team together and working fast. Invite them to use Hipchat.
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Inviting people to a room
It happens all the time, you're solving a problem, and just know that someone else in your team has the answers. Rather than starting a 1-to-1 chat with them, invite them to the room you're already chatting in.
If it's an open room, or a private room they're already a member of, the easiest way is to mention them in chat. If they're available they'll get a notification.
If it's a private room and they aren't a member of it, the room admin or a group admin will need to invite them to the room.