Md. Code, Business Regulation § 9A–504

Unless licensed to provide heating, ventilation, air-conditioning, or refrigeration services under this title, a person may not represent to the public by use of the titles “heating, ventilation, air-conditioning, and refrigeration license holder”, “registered heating, ventilation, air-conditioning, and refrigeration contractor”, by other title, or by description of services, methods, or procedures, or otherwise, that the person is licensed to provide or to assist in providing heating, ventilation, air-conditioning, or refrigeration services.