If you need to use a conference room for an impromptu meeting, or even to take a phone call, it is best to mark the room as in use on the iPad outside before going in.
Assuming the room is available, click "Start a Meeting"
Select the amount of time you need, you can adjust this in 15 minute increments using the + and - icons.
That's it, your meeting is started and anyone approaching the room will see that it is in use.
