No mention of this in Z FIDS that I can find, and not used sledging at Halley when we were there. It turned up with various odds and ends in an old Halley sledge box given to me about a decade ago. It’s from the mid 60s and could well have been used on the Totton trips.
We all heard of it being used on the Peninsula Bases but I never saw one so I wonder if this really is an example of the mysterious sledging ‘Dongler’ ?I did use a flag on one trip - over the load - this was just to get some colour into the photos!