I have had half a dozen iterations with Amazon, and am still not seeing a clue.
My Kindle collection, including C.J.S. Hayward: The Complete Works, is by physical construction converted from submitted, handcrafted, single-page HTML original documents. This and other works open with front matter, including a table of contents built in HTML, clearly intelligible but without any markup saying "This succession of
p.table-of-contents containing one link each is a table of contents."
Recently I received a Kindle quality notice that my book should have an NCX table of contents. I've repeatedly asked that Amazon either explain how to do that with a plain old HTML original, or withdraw the request. I've repeatedly been pointed to https://kdp.amazon.com/en_US/help/topic/G201605710 and failed completely in my efforts to communicate that the instructions given are ePub-specific and not an option in a single HTML file:
2. Use your TOC as an HTML TOC (recommended) For customers on older devices, this saves many clicks when they want to jump to a part of your book. Activate a guide item in the Kindle Go To menu to make a link to the HTML TOC accessible from anywhere in the book. To do this, reference your TOC in the navigation document with a landmarks nav element (sample code below). In the epub:type attribute, set "landmarks" as the value. In the epub:type attribute, add a link with "toc" as the value. Sample code: <nav epub:type="landmarks"> <ol><li><a epub:type="toc" href="table-of-contents.xhtml">Table of Contents</a></li></ol> </nav>
What, if any, options are there to make any appropriate changes that are feasible within an HTML source, and/or ask Amazon to stop asking for ePub-specific features on a single non-ePub HTML source?