There is the 1800m for IMC Rated pilots, under IFR, applicable to the UK only.
The same pilot (IMCR or IR) could depart "VFR" down to 1500m, which is quite funny because it's better than the above.
The 1800 m minimum visibility for take-off and landing for IMC-rated pilots is not limited to IFR.
I read somewhere that there is NO minimum vis for IR pilots departing IFR (private flight, obviously). Is this true, for both G and N?
Correct for G-reg. AD 1.1.2 3.4 refers
Also, is there a min vis for approaches, if no RVR is published for the airfield?
If no RVR is given, the equivalent must be calculated from met vis. AD 1.1.2 7.2 refers.
I know that airfields in CAS (Class D typically, and in Europe they will normally have full ATC) have written down departure limits for this; typically the min cloudbase is 1000-1500ft for a VFR departure. Presumably the RVR will apply to both departures and arrivals, VFR or IFR, no?
Rule 24(3) requires a pilot to use the reported visibility, and VFR will not be permitted if that is less than 5000 m. Since no cloud separation is required for VFR in class D in the UK, the ICAO 1500 ft minimum ceiling is not applied.