When you want to insert the sessions, you can choose in which conference room it will be held. You can create the conference rooms yourself.
Go to the abstract module > conference data and click on 'Conference Rooms'
The next screen will appear when you have clicked on conference rooms:
Click on New to insert a new conference room.
In the screen above you can insert the name and number of seats for the conference room. The number of rooms is only for your own information. When you click on accept you will return to the list conference rooms.