[hollowayhouse]

Thanks, Ducks.

I thought I'd done it correctly.
As to your suggested possibilities, I didn't do anything special when creating the ePub. I let Calibre do it with no special CSS or anything.

This was mainly an experiment to see if I could make it work.
I opened one html file, changed one word of text, not changing any code, saved it, closed it, rebuilt. Nada.

Odd, yes?