There is a good summary and comparison of eBook formats at Comparison of e-book formats (Wikipedia).

The number of different formats in some use is staggering and won't be of much interest to most people, but if you can zero in on the specific formats you're interested in and ignore all the rest, it may offer some good information about what approaches to using a few files different from your usual ones might be useful.

As posted, the page is quite large. (I had to copy in four separate "segments" to paste into Word to edit for readability, even with my "obscenely excessive" RAM installation) Snatching the bits of interest shouldn't be a problem for anyone, and (IMO) removing some of the extraneous stuff does make for easier comprehension - especially for Wiki stuff. Of course you have to remember you don't really have to save every document you create just to make something easier to read.

Probably not really of much interest to the originator of this thread, but might be worth a look for more "tech oriented" people, or any one with an interest in looking at several different formats(?).

John