As used in this article, unless the context clearly indicates otherwise:

1. (1) "Cooperative purchasing" means procurement conducted by, or on behalf of, more than one public procurement unit, or by a public procurement unit with an external procurement activity.

2. (2) "External procurement activity" means:

   1. (a) any buying organization not located in this State which would qualify as a public procurement unit;
   2. (b) buying by the United States government.
3. (3) "Local public procurement unit" means any political subdivision or unit thereof which expends public funds for the procurement of supplies, services, or construction.
4. (4) "Mandatory opting" is the requirement for a local procurement unit to choose whether to utilize a state contract before it is established as prescribed in regulation by the board.
5. (5) "Public procurement unit" means either a local public procurement unit or a state public procurement unit.
6. (6) "State public procurement unit" means the offices of the chief procurement officers and any other purchasing agency of this State.