Maryland Commercial Law Section 9-333
§ 9-333.
  (a)   In this section, "possessory lien" means an interest, other than a security interest or an agricultural lien:
    (1)   Which secures payment or performance of an obligation for services or materials furnished with respect to goods by a person in the ordinary course of the person's business;
    (2)   Which is created by statute or rule of law in favor of the person; and
    (3)   Whose effectiveness depends on the person's possession of the goods.
  (b)   A possessory lien on goods has priority over a security interest in the goods unless the lien is created by a statute that expressly provides otherwise.