The document discusses memorandum vouchers in Tally, which are non-accounting vouchers that do not affect the books of accounts but are stored in a separate register called the Memorandum Register. Memorandum vouchers can be used for items like suspense payments, vouchers not yet verified, and items given on approval basis. The document provides instructions on how to create and view memorandum vouchers and the Memorandum Register in Tally.