Any declaration, articles or agreement of trust of a business trust and any agreement of association of a voluntary association which provides for the use of a trade name shall authorize and designate or shall contain provisions for the authorization or designation of persons by whom deeds, leases, contracts and other written instruments shall be executed. All such deeds, leases, contracts and other instruments in writing shall be deemed to be properly acknowledged for the purposes of recordation if acknowledged in the form provided by statute for acknowledgments by corporations, or, if executed by trustees or other persons, then in the form provided by statute therefor.