This is when a guest has two folios, one for room and tax and the other for incidental charges. Most often used when the room and tax are going on the Master Account, and the guest (often a speaker, VIP or staff) is responsible for things like phone, in-room movies, mini-bar purchases, etc. It is also used when the guest is reimbursed for lodging and meals (e.g. Government employees), but must pay his/her own incidental expenses.