In reply to johncoxmysteriously:
The main rule from my quick research seems to be that you don't remove skis at any point, but any descent will have footnotes describing the style it was achieved in, a bit like in climbing. From Wiki:
'In ski mountaineering, the added dimension of the purity of the descent further muddies the standards at this time. Is the top the highest elevation of the snow line or is it the geological summit? Does a descent need to be continuous and what is the consideration for terrain in the middle of the mountain that is "un-skiable?" Does it matter if the skis come off during some portion of the descent to abseil a portion? While the standards of a mountaineering ascent still apply (including notation of O2 use), skiing, and the vagaries of "skiable" terrain add numerous variables to evaluating the purity of a descent.[6] Any database of ski descents is therefore likely to include heterogenous data.'
Wiki entry describes Andrzej's descent as:
summiteer; 1st summit to bc ski descent without removing skis