Does not belong to the accounting in the bookkeeping system, is not accounting when the books, it is the enterprise in order to strengthen the management of a certain aspect of the more detailed understanding of a certain aspect of information and set up a kind of auxiliary books, there is no fixed format, there is no fixed pages, the enterprise can be based on the actual needs of their own design, as detailed as possible, in order to comprehensively reflect a certain aspect of the information. It is not necessary to book by voucher number, but it is better to reflect the bookkeeping number. To be clear, the ledger is a running account. The opposite of the ledger should be the general ledger.