Regulation 10 was issued pursuant to c. 15 of the Ordinances of the City of Boston (1975), the Boston rent control ordinance. Under that ordinance, if a housing accomodation within the jurisdiction of the board is vacated after January 1, 1976, either voluntarily or by court order, the housing accomodation may be decontrolled.4 See Church v. Boston, 370 Mass. 598, 599 (1976). Regulation 10 provides the procedures to be followed in effecting decontrol: the landlord must file an application, accompanied by a statement that the previous tenant left voluntarily5 or pur*15suant to a court order. The board then must send notice to the former tenant of the application and supporting statement and inform the former tenant of the right to submit evidence or argument opposing the application within ten days after receipt of notice. The board may conduct an investigation into the facts alleged in the application and require the landlord to submit further facts and evidence. The regulation makes no provision for notifying the present tenant (hereinafter the new tenant) of the application, but does provide that “any party” may supply information and argument to the board within ten days of the filing of the application. If the board finds that there is probable cause to believe that the housing accomodation may not have been vacated voluntarily or pursuant to a court order, the board may order a hearing. The burden of proof is on the *16landlord throughout the application process. Following these proceedings the board is required to send notice of its decision to the landlord and the new tenant, and to any other interested parties. The notice must state reasons for the decision and that the decision may be appealed to the District Court6 or to the Housing Court.7