English to Italian Marketing Tourism & Travel Group Wash License/ Group Wash System

I am confused on the client's explanation of the word "wash" in this context, it is an e-learning tourism software application, the client gave me this explanation but to be honest i cant find an italian word to describe this, any ideas??? thanks in advance


Clients explanation: “Please find that in our system ‘Group Wash’ is defined as the difference between the final occupancy for a group and the maximum value of the block pace of the pickup pace. “