1SOn receiving any application for the registration of a rent, the rent officer may, by notice in writing served on the landlord or the tenant (whether or not the applicant or one of the applicants), require him to give to the rent officer, within such period of not less than 14 days from the service of the notice as may be specified in the notice, such information as he may reasonably require regarding such of the particulars contained in the application as may be specified in the notice.