\addcontentsline{file}{sec_unit}{entry}
The \addcontentsline command adds an entry to the specified list
or table where...
file is the extension of the file on which information is to be
written: toc (table of contents), lof (list of figures),
or lot (list of tables).
sec_unit controls the formatting of the entry. It should be one
of the following, depending upon the value of the file argument:
toc - the name of the sectional unit, such as part or subsection.
lof - figure
lot - table
entry is the text of the entry.