Maryland Code, BUSINESS REGULATION 4-302
(1) intercollegiate, interscholastic, or intramural boxing, kick boxing, or wrestling;
(2) amateur boxing conducted under the supervision of a nationally recognized amateur organization;
(3) martial arts where:
(i) contact to the body is permitted in only a restrained manner;
(ii) contact to the head is not permitted; and
(iii) no contact is permitted that may result, or is intended to result, in physical harm to an opponent; or
(4) a mixed martial arts exhibition.
(b) Each boxer shall wear protective headgear in each amateur boxing match or exhibition.