V refers to speed, as in VNE, Velocity not to exceed. In this case, Vmin IMC is the minimum speed for operating the aircraft under Instrument Met Conditions. Various others include Vbroc, Vtoss, etc. I'll leave you to work those out.
IVLL is the Installation & Vessel Landing Limitations list. This is a document produced by the CAA after consultation with the helicopter operators. It includes all platforms, semi-subs, resupply vessel, seismic vessels operating in the Northern and Southern North Sea and provides information concerning any obstructions etc which may hinder your approach, plus gives restrictions on the amount of pitch, roll and heave that are acceptable for the various helicopter types!!
Phew, that's the epistle according to Attila, I'm off for a beer.
