b. It means that even if you try to change the availability to "0", because you sold these beds on Hostelworld, Booking.com will answer to you that it is not possible because of contracted rooms. In HostelSystem you will see alerts like this with the content:
How to deal with it?
CONTRACTED BEDS IN DORMS
a. Our example - You contracted "2 beds" in "6 bed dorm".
b. You have Room 1 in HostelSystem with "6 beds". Until now, it was mapped with Hostelworld, Hostelbookers and Booking.com.
c. Now, in order to avoid overbookings, you must create 2 rooms in HostelSystem:
Before the change: Example
After the change: Example
When all beds are free, HostelSystem will send following availability to portals:
Hostelworld - 4 beds free
Hostelbookers - 4 beds free
Booking.com - 6 beds free
CONTRACTED PRIVATE ROOMS
This is much simpler case. If you have for example 3 x DOUBLE ROOM in your hostel, and one of the rooms was contracted with Booking.com, then simply map only 2 rooms for Hostelworld and Hostelbookers (and others), and all 3 rooms for Booking.com. For example:
Room 1 - Booking.com
Room 2 - Booking.com, Hostelworld, Hostelbookers
Room 3 - Booking.com, Hostelworld, Hostelbookers
This way, room 1 will only host guests from Booking.com.