If you're going on holiday, please log in and click 'I'm going on holiday' on your 'My Books page'.
This will deactivate all your books so no-one can agree swaps with you while you are away.
When you come back, simply go to 'My Books' and click 'I've returned from holiday' and all the books you want to swap will return to your active list.
Do NOT use the "Make All My Books Inactive" option if you're only going to be away from the site for a short while. If you use this option, when you want to start swapping again you will have to make ALL your books active again including all the books you've received as swaps but don't want to relist for swapping just yet.