4. Registrants based in Ontario and domiciled in Canada, with the exception of limited partnerships, who are building contractors subject to the Ontario-Quebec Agreement on Public Procurement and Construction Labour Mobility of 24 December 1993 or to any other subsequent agreement entered into by the Gouvernement du Québec and the Government of Ontario as regards mobility in the construction industry are exempted from the requirement to designate an attorney in accordance with section 26 of the Act.