Okla. Const. art. IX, § 34

As used in this Article, the term "transportation company" shall include any company, corporation, trustee, receiver or any other person owning, leasing or operating for hire a railroad, street railway, canal, steamboat line, and also any freight car company, car corporation, or company, trustee or persons in any way engaged in such business as a common carrier over a route acquired in whole or in part under the right of eminent domain, or under any grant from the Government of the United States; the term "rate" shall be construed to mean rate of charge for any service rendered, or to be rendered; the terms "rate," "charge" and "regulation" shall include joint rates, joint charges and joint regulations, respectively; the term "transmission company" shall include any company, receiver or other person owning, leasing or operating for hire any telegraph or telephone line; the term "freight" shall be construed to mean any property transported or received for transportation by any transportation company. The term "public service corporation" shall include all transportation and transmission companies, all gas, electric, heat, light and power companies, and all persons, firms, corporations, receivers or trustees engaged in said businesses, and all persons, firms, corporations, receivers or trustees authorized to exercise the right of eminent domain or having a franchise to use or occupy any right of way, street, alley or public highway, whether along, over or under the same, in a manner not permitted to the general public, and all persons, firms, corporations, receivers and trustees engaged in any business which is a public utility or a public service corporation, at the present time or which may hereafter be declared to be a public utility or a public service corporation. The term "person" as used in this Article shall include individuals, partnerships, and corporations in the singular as well as plural number; the term "bond" shall mean all certificates or written evidence of indebtedness issued by any corporation and secured by mortgage or trust deed. The term "frank" shall mean any writing or token issued by or under authority of a transmission company, entitling the holder to any service from such company free of charge.

The provisions of this Article shall always be so restricted in their application as not to conflict with any of the provisions of the Constitution of the United States, and as if the necessary limitations upon their interpretation had been herein expressed in each case.