The following words or terms, when used in this Subchapter, shall have the following meaning, unless the context clearly indicates otherwise:
"Participating employer" as defined in Section 902(25) of Title 74 of the Oklahoma Statutes means an eligible employer who has agreed to make contributions to the System on behalf of its employees provided such employer is the State, a political subdivision of the State, or an agency or instrumentality of the State. Participating employer shall not include any employer which is not permitted to participate in a qualified governmental pension plan as defined in Internal Revenue Code Section 414(d), 26 U.S.C. §414 (d).
Okla. Admin. Code § 590:10-2-1