W3cubDocs

\subsubsection, \paragraph, \subparagraph

Synopsis, one of:

\subsubsection{title}
\subsubsection*{title}
\subsubsection[toc-title]{title}

or one of:

\paragraph{title}
\paragraph*{title}
\paragraph[toc-title]{title}

or one of:

\subparagraph{title}
\subparagraph*{title}
\subparagraph[toc-title]{title}

Start a subsubsection, paragraph, or subparagraph. The standard LaTeX classes article, book, and report all have these commands, although they are not commonly used.

This produces a subsubsection.

\subsubsection{Piston ring compressors: structural performance}
Provide exterior/interior wall cladding assemblies
capable of withstanding the effects of load and stresses from 
consumer-grade gasoline engine piston rings.

The default output of each of the three does not change over the standard LaTeX classes article, book, and report. For \subsubsection the title is alone on its line, in boldface and normal size type. For \paragraph the title is inline with the text, not indented, in boldface and normal size type. For \subparagraph the title is inline with the text, with a paragraph indent, in boldface and normal size type (Because an article has no chapters its subsubsections are numbered and so it looks like ‘1.2.3 title’, for section 1, subsection 2, and subsubsection 3. The other two divisions are not numbered.)

The * form shows title. But it does not increment the associated counter and produces no table of contents entry (and does not show the number for \subsubsection).

The optional argument toc-title will appear as the division title in the table of contents (see Table of contents etc.). If it is not present then title will be there.

For determining which sectional units are numbered and which appear in the table of contents, the level number of a subsubsection is 3, of a paragraph is 4, and of a subparagraph is 5 (see Sectioning/secnumdepth and see Sectioning/tocdepth).

The paragraph that follows the subsubsection title is not indented, as is a standard typographical practice. One way to get an indent is to use the package indentfirst.

There are a number of ways to change the behavior of the these commands. One is the \@startsection command (see \@startsection). There are also many packages on CTAN that address this, including titlesec. See the documentation on CTAN.