(a) Generally. A defendant, in person or by counsel, may plead guilty, not guilty, or, with the consent of the court, nolo contendere. (b) Pleas of Guilty and Nolo Contendere. The court shall not accept a plea of guilty or a plea of nolo contendere without first determining that the defendant has been advised of all rights set forth in Rule 210(a)(4) and also determining: (1) That the defendant understands the nature of the charge and the effect of the plea; (2) That the plea is voluntary and is not the result of undue influence or coercion on the part of anyone; (3) That the defendant understands the right to trial by court, or by jury, if applicable, and that the plea waives the right to trial on all issues; (4) That the defendant understands the possible penalty or penalties. (c) Absence of the Defendant. The court may accept, in the absence of the defendant, any plea entered in writing by the defendant or counsel or orally made by counsel. (d) Failure or Refusal to Plead. If a defendant refuses to plead or if the court refuses to accept a plea of guilty, or a plea of nolo contendere, or if a corporation fails to appear, the court shall enter a plea of not guilty. If for any reason the arraignment here provided for has not been had, the case shall for all purposes be considered as one in which a plea of not guilty has been entered. Entire chapter amended June 30, 1988, effective 1/1/1989. ANNOTATION Although the defendant was advised of several rights and the possible penalties, he was not advised of his constitutional right to be represented by counsel, and the trial court properly ruled that the municipal court's advisement of the defendant was illegal since it did not meet the mandatory requirements set forth in this rule. Mulkey v. Sullivan, 753 P.2d 1226 (Colo. 1988). Where the defendant has entered a plea of guilty and later wishes to withdraw such plea, the burden is on the defendant to present a prima facie case that the plea was not knowingly and understandingly made. City of Colo. Springs v. Forance, 776 P.2d 1107 (Colo. 1989).