Md. Code, Business Occupations and Professions § 9.5–103

(a) A crane operator who holds a Certificate of Competence shall:

(1) carry the Certificate of Competence while operating a crane in the State; and

(2) make the Certificate of Competence available for inspection on request by the Commissioner, an agent of the Commissioner, or by a law enforcement officer.

(b) The failure of a crane operator to make the Certificate of Competence available for inspection on request as required under paragraph (a)(2) of this subsection shall be presumptive evidence that the crane operator does not hold a Certificate of Competence.