One of the extra complexities for us poor souls who fly in the UK is that it is mandatory to fly IFR at night. So we get this half-baked situation where you have to fly IFR, but you don't need an IR (just a night rating for PPLs) or a twin IFR-certified helicopter if you fly "visual contact" flight in uncontrolled airspace (Class F&G). However, if you want to fly in controlled airspace this special night rule does not apply - you must have an IR and fully IFR helicopter - unless of course you get an SVFR clearance.
In this case, the IFR definitely refers to the RULES you fly under and not the met conditions which need to be "visual".
This is so confusing that you often see CAA publications misunderstanding what the requirements are. We spend so long working out what to do for night flights it is usually dawn before we get airborne, which sorts the problem anyway.
