\chapter, or should that be \section, or should that be \subsection, or \subsubsection etc, depending on which layout you are using. \part maybe?
But then surely the h1 document title should be above that, which would be "=" (1), so a chapter is below at "==" (2)?
\part apparently is -1 in latex, which would be seem to be odd.
But document title isn't part of the latex sectioning hierarchy...
Given that there is a document title, part and chapter, chapter could maybe "===" (3) or maybe "==" (2) if we're not using parts or we don't consider the document title.
I think anyway?
It's unfortunate that the creators of latex did not follow the HTML heading rules better. (despite latex pre-dating html of course)
:-)