The following words or terms used in this act shall have the following meanings unless a different meaning clearly appears from the context:
(a) "Bonds" means any bonds, notes or other evidences of indebtedness, including book-entry-only, whether or not the interest on such bonds is subject to federal income taxation, issued pursuant to the authority of this act.
(b) "Secretary" means the secretary of transportation.
(c) "Book-entry-only" means a system of electronic clearance, settlement and transfer of security ownership without the use of securities certificates.