VIDT VI Vitis romanetii vat. arachnoidea Vigna angularis Var. nipponensis vitrinite reflectance distribution virtiol fractional crystallization vitrification of radioactive waste Vitelline blood vessel of placenta VI. Arms Control and Disarmament Vitexin beta-glucosyltransferase Vitex trifolia var. simplicifolia VILP Vector Impedance Locus Plotter