Griss and Chris:

However, I've decided that for my purposes (and those of my own and ski
club kids, and most
adults), the methods using body landmarks are easiest and best.

It makes sense....and fits with the way I purchaced my gear. What
didn't make sense, was the discrepancy between the number yielded by the
formula, and my actual pole length (nearly 5 cm in one case).

clear as mud?

Absolutely! "referential" makes much more sense. It did make me wonder
though.