You can create a rule that allows your inventory to have more or less availability depending on certain conditions by using the Set Availability action.
For example, if you need to block out a tour's availability for a specific date, you could use the Date being booked condition to select the date, the Inventory Item condition to select that particular tour, and the Set Availability action to decrease its availability.
To create a rule that uses the Set Availability action, follow these steps:
1. Navigate to Inventory > Rules in the main menu.
2. Click Create Rule.
3. Give your rule a name that's easy to recognize, and a description of what it will do.
4. Click Add New Action.
5. Click Set availability to…
6. Select whether the rule should set, increase or decrease the included items' availability.
7. Enter the number you want to set the availability to, or the number you want to increase or decrease it by.
9. Click Create Rule.