Md. Code, Com. Law § 12-902

(a) Any credit grantor may, subject to the other provisions of this subtitle: (1) Offer and extend credit under a revolving credit plan to a borrower and in that connection charge and collect the interest, finance charges, and other charges permitted by this subtitle; (2) (i) Take any security as collateral as may be acceptable to the credit grantor. (ii) If real property is taken as security, the credit grantor shall record the entire line of credit when the credit plan is established. (b) Without limiting subsection (a) of this section, credit may be extended under a revolving credit plan by a credit grantor’s acquisition of obligations arising out of the honoring of a credit device made available to a borrower under a plan, whether directly or indirectly by means of telephone, point of sale terminal, automated teller machine or other electronic or similar device, or through the mails, by: (1) A merchant; (2) A bank or other financial institution chartered or organized under the laws of this or any other state, the District of Columbia, the United States or any district, territory, or possession of the United States, or any foreign country; (3) Any other person or entity; or (4) A government or governmental subdivision or agency.