TASC is an acronym for "TransAtlantic Inter-Society Consensus" group. In 2000, this group presented a consensus document of vascular specialists based on sound data on epidemiology, diagnostics and therapy of PAVK. The classification of lesions was based on their localization (aorto-iliac, femoropoliteal, infrapopliteal), the extent of the lesions (stenosis, occlusion, single vs. multiple lesions) and the extent of the lesions (in centimeters).