Okla. Stat. tit. 59, § 2045

A. Nothing contained in the Respiratory Care Practice Act shall preclude a respiratory care practitioner, a respiratory therapist, or a respiratory therapy technician exempt from being licensed under the Respiratory Care Practice Act or a provisional license holder from using or displaying earned professional designations or credentials including, but not limited to, CRTT, RRT, CPFT and RPFT. However, a respiratory care practitioner may use and display the designation Respiratory Care Practitioner or RCP in conjunction with the use or display of any such other earned professional designation or credentials. B. A provisional or special provisional license holder shall not use or display the designation Respiratory Care Practitioner or RCP but may use or display any earned professional designations or credentials.