MEL - Minimum Equipment List. A requirement for all modern public transport aircraft, it lays down what may be unserviceable before flight and the corresponding limitation. Crews must adhere to the MEL The VC10 pre-dated this requirement; it does not have a 'go / no go' list either, it has a list of recommendations in the Topic 2R1 (or whatever it's called now) which are for aircrew guidance only and not for the groundcrew to think of as a 'no go' reference document.
ELRAT - Electrical Ram Air Turbine. Certain electrical failures require this to be lowered; it provides emergency electrical power because, unlike modern aircraft or even the Vulcan, the VC10 auxiliary power unit cannot be used in flight. It powers a limited number of powered flying control units and other systems. Way back it was also planned to fit a HYDRAT to provide emergency hydraulic power, but this was not fitted to production aircraft.
ECAM - Electronic Centralized Aircraft Monitor system. As fitted to all Airbus aircraft, but emphatically NOT the VC10! Any system caution or warning will cause an appropriate chime, description of failure and action to be taken. Boeing have something similar, termed Engine Instrumentation and Crew Alerting System (EICAS). The ancient VC10 has a food-powered systems monitoring system (termed the air engineer), plus various bells, klaxons, lights and gauges scattered around the flight deck.