1. (a) If a document is sent by United States Registered Mail or by a delivery service designated in OAC 710:1-3-33, the date of registration of the document shall be treated as the postmark date.
2. (b) If a document is sent by United States Certified Mail or by a delivery service designated in OAC 710:1-3-33, and the sender's receipt is dated by the service's employee, the date on the receipt shall be treated as the postmark date of the document.

Amended at 22 Ok Reg 1513, eff 6-11-05