Okla. Stat. tit. 22, § 22-513: Pleas to indictment or information

There are four kinds of pleas to an indictment or information. A

plea of:

First, Guilty.

Second, Not guilty.

Third, Nolo contendere, subject to the approval of the court.

The legal effect of such plea shall be the same as that of a plea of

guilty, but the plea may not be used against the defendant as an

admission in any civil suit based upon or growing out of the act

upon which the criminal prosecution is based.

Fourth, A former judgment of conviction or acquittal of the

offense charged, which must be specially pleaded, either with or

without the plea of not guilty.