PS: Search this Kindle document repeatedly on "Table of Contents" for a somewhat obtuse and confusing discussion of the difference between NCX and TOC -- "TOC" which this document refers to as "HTML TOC." The OPF specs also confuse this issue by unfortunately choosing the arbitrary name "toc" for their ncx example files!
http://s3.amazonaws.com/kindlegen/Am...elinesV1.3.pdf