For many years my primary writing tool has been Microsoft Word. It seems to be the standard. All my recent writing has been in Word 11 for the Mac. All versions since Word 2000 have the ability to automatically generate a hyperlinked Table of Contents. Within an e-book, this means one can go to the beginning of a book, find the Table of Contents, and click on any Chapter Heading, map or table designator and go directly to the item in question.
After I had uploaded my first title to Smashwords, I found a warning regarding having hidden code in my document. I knew nothing of hidden code, but eventually found I had hidden code in my auto-generated Table of Contents created in Microsoft Word. I had to return to my original document, strip the hidden code, and painstakingly rebuild a hyperlinked Table of Contents. With that done, Smashwords approved my title for its premium catalog.