Regular customers. Generally speaking, the company or unit has an agreement with the hotel, frequenting it, and can sign the bill after each meal. Of course, it is generally limited to the boss or senior salesman, and then the hotel will collect bills from the company or unit on a monthly or quarterly basis. Signing a bill means that after shopping, catering and other consumption, you don't pay cash, you sign your name on the bill, and then the store will settle the bill.