jf42, I've followed many of your posts and seriously doubt I'm ahead of you on anything
You're right, I'm afraid, and I still don't know for certain whether the term was common parlance among the British on that date. Reminiscences and memoirs are too dependent on hindsight to be of much value here, and the usually reliable letter writers (eg Paget, Dallas, Buchanan et al - and even the 93rd's own Colonel Sterling) are all horribly silent on the subject.
It does, however, seem very likely that it was, since Russell uses the name specifically in his original report for the Times on the Battle of Balaklava. I certainly HOPE that it was, as I've risked using the term for the sake of clarity, and that particular book has now gone to print. It'll come out in May - when I expect to receive 500 letters telling me I've got it wrong.
I guess it's a small price to pay for knowledge...