Many airfields have multiple QFEs in force at the same time. An unqualified (airield) QFE means that when the altimeter subscale is set to the QFE the altimeter displays your height above the airfield reference point (usually the mid-point of the main runway). You may be offered a runway threshold QFE, which is relevent for a sloping runway, and then the alimeter will display your height above the threshold for that runway. That will only apply if the runway threshold is more than 7' below the reference point for airfield QFE.