Maryland Code, Commercial Law § 11-805

(a) Except as provided in subsection (c) of this section, if a third person takes goods or a possessory document in deposit or pledge as security for a preexisting debt or demand from any other person entrusted with them or to whom they are consigned or who is entrusted with and in possession of a possessory document, he acquires only the right, title, or interest as was possessed and might have been enforced by the person from whom he received the goods or possessory document.

(b) Except as provided in subsection (c) of this section, if a third person knows that he is dealing with a consignee, he may take goods or a possessory document in deposit or pledge as security for a preexisting debt or demand, but he acquires only the right or interest in the goods or possessory document that was possessed by the consignee at the time of the deposit or pledge.

(c) If a third person has notice that the consignee is not authorized to pledge, deposit, or part with possession of the goods or possessory document, he acquires no right, title, or interest in the goods.