Decides: (a) to call upon the parties concerned to implement immediately Security Council resolution 338 (1973) of 22 Oct. 1973; (b) to renew the mandate of the UN Disengagement Observer Force for another period of 6 months, that is, until 30 Nov. 1988; (c) to request the Secretary-General to submit, at the end of this period, a report on the developments in the situation and the measures taken to implement Security Council resolution 338 (1973).