drxx rad
Thanks for your comments. I made the same mistake as rad re terminal letter.
I was surprised that the pre-amble made no reference to clashing letters and that puzzled me throughout, but it became clear in the end. Also thought "items of a similar description" was unhelpful.
Pleased with myself as I have never finished a Kcit puzzle, and I did it without help. I will enter and email Editor. Very enjoyable as the excellent series continues.