Okla. Admin. Code § 455:10-13-4
At the written request of a party, the Executive Director or presiding official may order discovery if the request includes a statement of the issues in dispute; a proposed plan and schedule for discovery; any proposed limitations; and a statement showing that a reasonable effort to reach agreement with the opposing party on the matters set forth in the request has been made. The request shall include an affidavit of service to all other parties by submission on the on-line filing system. A response may be filed within 10 calendar days after the request is filed with the Commission and shall include an affidavit of service to all other parties by submission on the on-line filing system. The presiding official may rule on discovery requests at the prehearing conference or preparation conference.
Okla. Admin. Code § 455:10-13-4