The owner and operator and lessor of any building within the City containing more than two dwelling units or at least one dwelling unit in an otherwise commercial building shall, upon a form provided therefor by the Building Commissioner and available at his office, register the premises by designating thereon the name and address of the owner, the name and address of any lessor operator other than the owner and the name and address of an agent in charge of the premises residing in the Municipality who may be the owner, operator or lessor. If there is more than one (1) person as owner, operator or lessor, then separate or a single combined registration may be filed as the person may elect.