045-4 Wyo. Code R. § 4-3
(a) Plates shall be issued using only capital letters and Arabic numerals. No other symbols or characters shall be allowed. Applicants may request a maximum of four letters or a combination of four letters and numerical digits. The letters and numbers shall be the same size as on regular license plates and shall be arranged in a straight horizontal line.
(b) Any combination that spells, connotes, abbreviates, or otherwise stands for obscene, vulgar, indecent, or pruriently suggestive language shall not be allowed. No four-character combinations shall contain more than a total of three W's or three M's. No combinations consisting of a number or numbers followed by a single alphabetic suffix shall be issued as a personalized prestige license plate. Nor shall combinations consisting entirely of numbers be issued for prestige plates unless the beginning digit is a zero (0). In addition, no combination shall duplicate a currently issued plate or conflict with a series of letter and number combinations on a regularly issued license plate.
045-4 Wyo. Code R. § 4-3