Maryland Commercial Law Section 13-317
(a)   Except as provided in subsection (b) of this section, as a condition of accepting a credit card or device as payment for consumer credit, goods, realty, or services, a person may not record the address or telephone number of the credit card holder.
(b)   A person may record the address or telephone number of a credit card holder if:
(1)   The information is necessary for:
(i)   The shipping, delivery, or installation of consumer goods; or
(ii)   Special orders of consumer goods or services;
(2)   Authorization from the credit card issuer as to the availability of credit is not required by the issuer to complete the credit card transaction; or
(3)   The person processes credit card transactions by mailing transaction forms to a designated bankcard center for settlement.
(c)   A person accepting a credit card or device as payment for consumer credit, goods, realty, or services may request that the credit card holder display a form of identification.