According to JAR/EU Ops you are not allowed to make app. CAT I below RVR750m without FD (or HUD) to the airfields without RWY Tochdown Zone Lights or RWY Centerline Lights. For full-facility equipped runways you don't need to have FD, so you are allowed to make it.
And as tommoutrie wrote here, you need FD and 800m for single pilot operations.
But the number 1200m is really strange for me
It's popular that TREs like to fly according to their company's OM.
Cheers!