Art. 27.16. PLEA OF NOT GUILTY, HOW MADE.  (a)  The plea of not guilty may be made orally by the defendant or by his counsel in open court.  If the defendant refuses to plead, the plea of not guilty shall be entered for him by the court.
(b) A defendant charged with a misdemeanor for which the maximum possible punishment is by fine only may, in lieu of the method provided in Subsection (a) of this article, mail to the court a plea of not guilty.
Acts 1965, 59th Leg., p. 317, ch. 722, Sec. 1, eff. Jan. 1, 1966.  Amended by Acts 1977, 65th Leg., p. 2143, ch. 858, Sec. 2, eff. June 16, 1977.