law: 10. Power to require and enforce the making of statements as to names and interests.-
  The Collector may also require any such person to make or deliver to him, at a time and place mentioned (such time not being earlier than fifteen days after the date of the requisition) a statement containing, so far as may be practicable, the name of every other person possessing any interest in the land or any part thereof as coproprietor, sub-proprietor, mortgagee, tenant or otherwise, and of the nature of such interest, and of the rents and profits (if any) received or receivable on account thereof for three years next preceding the date of the statement.