Md. Code Ann., Tax-Prop. § 11-102

(a) The Department may require a person to submit to the Department a report on personal property that contains the information listed in subsection (b) of this section, if the person: (1) moves personal property to any county or municipal corporation from the county or municipal corporation where it was assessed; (2) moves personal property from outside this State to a county or municipal corporation inside this State; or (3) possesses, cares for, or manages any personal property that: (i) is not assessed; or (ii) the Department suspects is not assessed.

(b) The report on personal property shall contain: (1) a list of: (i) all personal property assessable by the Department; and (ii) all personal property assessable but not previously assessed by the Department that the person possesses, cares for, or manages; and (2) the name of each person who owns an item of the personal property.