Welcoming also the agreement in principle to the Secretary-General 's package by the Government of Morocco and recalling its acceptance by the POLISARIO Front , 1 . Decides to extend the mandate of the United Nations Mission for the Referendum in Western Sahara ( MINURSO ) until 30 April 1999 to allow for an understanding to be reached among all concerned on detailed modalities for the implementation of the identification and appeals protocols , including a revised implementation schedule , in a manner that would preserve the integrity of the Secretary-General 's package of measures ; 2 .