In reply to Jim Fraser:
> How can there be a Scottish winter equivalent to a grading that is not intended for rimed rock, frozen cracks and turf?
You're wrong, M-grades can be used for all that, and they are.
At least to me, this looks very much like some of the photos I've seen from Scottland
http://1.bp.blogspot.com/-GEIqrDmBces/UXF6Id7oTQI/AAAAAAAAHPw/RIJhveyvNtY/s...
But oddly, it is given a M -grade (after all, it was climbed with crampons and ice tools, plus involved ice, snow, rock and most likely also frozewn moss...
Here's some other M -graded climbs...
http://4.bp.blogspot.com/-HmaB4ELJ5qA/US36MVrMAcI/AAAAAAAAG1A/lrIH9ckmgAs/s...