Unfortunately, we in the military have changed the altimeter setting procedures rather more frequently than some aviation publications could keep up with. We used to be 100% QFE, then we went 100% QNH but the pointy-heads couldn't cope with that, so we went back to QFE!! Basically, should you need to enter a MATZ, nowadays you'll be given the QFE and be expected to fly on that. Incidentally, you don't HAVE to request MATZ penetration as a MATZ is only Class G. But you DO have to recognise the associated ATZ. Some military aerodromes (e.g. Brize Norton and Lyneham) have Class D Control Zones rather than MATZs; the normal rules for entering Class D airspace then apply. To make it really confusing, flight within the Brize Norton Control Zone is by QFE, but some civil aircraft use QNH...and the zone has a limit of 3500' QNH, but most RAF aircraft still change from QFE to SPS at 3000' QFE........AARRGH!!!!