(a) All work papers used in calculating account balances and transaction totals shall be permanently maintained as part of the general ledger.

(b) If account balances and transaction totals are not posted directly to the accounts but are posted from entries or totals contained in another system of accounts, such books, including general and subsidiary ledgers and supporting books and records shall be preserved as long as the books of account prescribed by the URS are preserved.

(c) All reports shall reflect the accrual basis of accounting. Generally accepted accounting principles shall be used in establishing the accounting treatment of any financial transaction, except that the commission may require such accounting treatment as will yield information necessary to a proper discharge of the commission' s responsibilities.