Hmmmm, it appears this has changed recently (black mark next to the paragraph, meaning it's been changed in the latest ammendment).
What I used to believe was the case, was any approach you did using Area QNH (regardless of the weather services provided), you added 50ft to the minima that did NOT account for accurate QNH.
What it now appears to say, is if the aerodrome you are conducting the approach into, is NOT subject to any weather service (TAF, TTF, METAR, AWIS/B) at any time, then it assumes that you will always be conducting an approach using Area QNH, therefore the minima has been worked out based on that assertion.
BUT, if the aerodrome DOES receive a weather service (even if not full time), if you shoot an approach using the Area QNH, then throw another 50ft onto the minima that doesn't allow for an accurate QNH.
There, clear as mud,
. And thank you for alerting me to this piece of useful information that has changed,
.
morno