Maryland Real Property Section 14-311

      (a)      A commercial leasing brokerage agreement between a broker and an owner may not waive or require the broker to waive the right to claim or establish a broker's lien.

      (b)      Any waiver provision made in a commercial leasing brokerage agreement or any other contract, express or implied, between a broker and an owner made in violation of this section is void as a matter of public policy.