[dlw]

Thanks for thinking about this, HarryT and theducks, but . . . it doesn't work for me.

Have you had success linking from one file to another? If you haven't actually tried it, I've attached SigilLinktest.epub that demonstrates Sigil's link reduction. If you load this into Sigil you'll see that it reduces each cross-file link style to #CH02-01. This makes ebook readers try to find the link in file01.html -- the currently-open file -- which, of course, they can't.

Thanks again for your thoughts.