Yikes! I've read a number of authors' posts who are thoroughly confused by the formatting aspect of publishing an ebook. The only instructions I've seen assume writers use MS Word, and I think many do not, so they may not be familiar with the concepts used in those formatting guidelines.
IMO, it's something a self-publishing author MUST get right. If I download a sample (and I always do) and see that the formatting isn't right, I absolutely will not buy the book. There are far too many books to read and far too few years left to put up with frustrations like bad formatting.
