The price variables can have an optional offset value applied which can be a percentage or fixed amount with or without minus sign added after a colon, for example '''[PRICE:-10]''' or '''[INVOICEBALANCE:25%]'''
== Property Variables ==
[PROPERTYNAME] - property name
== Room Variables ==
[ROOMNAME] - room names of all booked rooms
[UNITNAME1] - unit name of the first assigned room
== Booking Variables ==
[BOOKID] - booking reference