What is the memorandum book for discounting bills receivable?

Find a notebook and write down the details of the bills discounted by the enterprise, which generally include: discount time, fee, discount amount, bill maturity date, whether the payer fails to pay at maturity and whether the enterprise bears joint liability, etc.

Because these items can't be recorded in the enterprise's account book, you have to find another account book to record, which is more convenient for inquiry.

That's what it means.