(a) The following books of account and voucher forms are prescribed to operate the double-entry set of books, kept on the accrual basis, prescribed in section 1640-1.3:

(b) The obligation of the local agency to keep the prescribed books and records accrues as of the date of the contract for State aid. (See § 1640-4.3 for books and records to be kept prior to the date of the contract for State aid.) A complete set of books and records shall be maintained for each State-aided project and shall be kept separate and distinct from all other accounts, records and books of the local agency.

(c) The books of account established at the beginning of the development period will be continued into the operating period, the appropriate columns in the books of original entry and the subsidiary ledgers for the operating period merely being added, as required. The various books of account and voucher forms are described in succeeding paragraphs of this section. The use of bound books is not prescribed, the loose-leaf arrangement being preferred. Recommended forms, suitable for either loose-leaf or bound books, are illustrated in the exhibits of Appendix S-8. The use of forms identical with those exhibited is not prescribed and the forms illustrated may be modified in a reasonable manner, so long as the modified forms show the required information, as per the exhibits. The forms are of standard design and may be procured from most stationers or adapted from stock forms. It may, however, be found necessary to have the voucher forms specially printed.