Specifies the maximum depth of the navigation table of
contents.
This property controls the depth of navigation tables of contents, such
as left-nav trees for HTML5 output and the EPUB navigation toc. This is
distinct from any HTML table of contents that might get generated. For
example, Apple uses the practice of a single-level navigation ToC in
EPUBs.
Value
An integer from 1 to n.
Default
The default is the value of the d4p.max.toc.depth parameter,
which itself defaults to "5".