Add \subsubsubsection to a Hitec Latex document

So what if you need to divide a \subsubsection{} into even lower subsections? LaTeX classes don’t usually support that, because if you need that feature, your document’s structure is wrong. Or so they say. You should have chopped the document with \part{} or \chapter{} at a higher level, and not cut down the sections into even smaller pieces.

But with technical documentation (say, outlining an API) it can be very handy with something below \subsubsection{}. As it turns out, LaTeX actually supports lower levels, but they aren’t numbered by default. So it goes:

1. \section{}
2. \subsection{}
3. \subsubsection{}
4. \paragraph{}
5. \subparagraph{}

That’s neat, isn’t it? In order to make the two last numbered, add this to the LaTeX document:

\setcounter{secnumdepth}{5}
\setcounter{tocdepth}{5}
\titleformat{\paragraph}
{\normalfont\normalsize\bfseries}{\theparagraph}{1em}{}
\titlespacing*{\paragraph}
{-15ex}{3.25ex plus 1ex minus .2ex}{1.5ex plus .2ex}
\titleformat{\subparagraph}
{\normalfont\normalsize\bfseries}{\thesubparagraph}{1em}{}
\titlespacing*{\subparagraph}
{-12ex}{3.25ex plus 1ex minus .2ex}{1.5ex plus .2ex}

After adding this, sub-sub-sub-section numbers appear with \paragraph{}, and even one more level down with \subparagraph{}.

\label{} works as expected (\ref{} correctly references \paragraph{} and \subparagraph{}), and the table of contents also lists these elements neatly.

This snippet works well with the Hitec class. I don’t know if it works with other classes. But even if it does, odds are that the result will look ugly, as this code defines the spacing so that it looks fairly nice with Hitec’s formatting.

So it’s not really \subsubsubsection{}, which is awkwardly long anyhow, but a more elegant solution.