The blacklist is a list where you can put a guest who caused problems so that the system can let you know if the same guest books a stay again in your property.
If you have more than one property you can share the blackist among group of your properties. Let us know to email@example.com in case you are interested in this option.
You can find the blackist here:
In order to put a guest on a blacklist go to Guest Details in reservation window and click on Blacklist checkbox:
Once you click on it you will see a pop up where you can enter the reson and the severity of the issue:
You can also add a guest directly in the blackist:
In order to unblacklist a guest you can uncheck the blacklist box in the reservation window
or click on Unblacklist guest here