To set up automatic room holding, called "Hold Rooms," start by checking which kind of release you'd like to hold, from either cancelled rooms, or change requests. This is done in the Event Hotel page.
Let's first start with going over the logic used to determine "Public Availability" and how held rooms comes into play. Your typical inventory page would work by taking the number of allocated rooms, and subtracting how many rooms have been booked by your attendees. The result is called "Main Available". Pretty simple. With Hold Rooms, however, there is additional layer of logic added to the equation. With your Main Available inventory, what happens next is you subtract the number in both the "Hold Rooms" and "User Held" rows, to get a final number of live rooms called "Public Available."
Held Rooms: These fields will automatically increase when a room night becomes available as result of a change request or cancellation. These fields can only be decreased by the Master Control Panel when you want that inventory to show as available in the main-block again.
User Held: These are room nights you want to manually hold in the system. This field can either be increased or decreased by any Master Control Panel user.
With the feature enabled, you will see two new view modes from the view drop-down called "Show Hold Rooms" and "Show User Held".