Frequently Asked Question List for TeX

# How to create a `\subsubsubsection`

LaTeX’s set of “sections” stops at the level of `\subsubsection`. This reflects a design decision by Lamport — for, after all, who can reasonably want a section with such huge strings of numbers in front of it?

In fact, LaTeX standard classes do define “sectioning” levels lower than `\subsubsection`, but they don’t format them like sections (they’re not numbered, and the text is run-in after the heading). These deeply inferior section commands are `\paragraph` and `\subparagraph`; you can (if you must) arrange that these two commands produce numbered headings, so that you can use them as `\subsubsubsection`s and lower.

The `titlesec` package provides a sensible set of macros for you to adjust the definitions of the sectioning macros, and it may be used to transform a `\paragraph`s typesetting so that it looks like that of a `\section`.

If you want to program the change yourself, you’ll find that the commands (`\section` all the way down to `\subparagraph`) are defined in terms of the internal `\@startsection` command, which takes 6 arguments. Before attempting this sort of work, you are well advised to read the LaTeX sources (`ltsect.dtx` in the LaTeX distribution) and the source of the standard packages (`classes.dtx`), or to make use of the LaTeX Companion, which discusses the use of `\@startsection` for this sort of thing.

You will note that Lamport didn’t go on adding `sub` to the names of sectioning commands, when creating commands for the lowest levels of a document. This would seem sensible to any but the most rigorous stickler for symmetry — it would surely challenge pretty much anyone’s reading of the source of a document, if there was a need to distinguish `\subsubsubsection` and `\subsubsubsubsection`

FAQ ID: Q-subsubsub
Tags: structure