Maryland Code, Election Law § 13-245

(1) distributing campaign material;

(2) stationing a person, including oneself, or an object in the path of a voter;

(3) electioneering or canvassing as described in § 16-206 of this article;

(4) communicating in any other manner a voting preference or choice; or

(5) performing any other service as a poll worker or distributor of sample ballots.

(1) meals, beverages, and refreshments served to campaign workers;

(2) salaries of regularly employed personnel in campaign headquarters;

(3) media advertising, including newspaper, radio, television, billboard, or aerial advertising;

(4) rent and regular office expenses; or

(5) the cost of telephoning voters or transporting voters to and from polling places.

(c)(1) A campaign finance entity, or a person acting on its behalf, may not at any time, directly or indirectly, pay or incur an obligation to pay, and a person may not, directly or indirectly, receive any money or thing of value, for a political endorsement.