# How can I keep sectioning but disable its display

I'm quite happy with titlesec and titleps for keeping track of sections and creating footers that are conditional on whether a chapter start or is continued, but there was a case where it wasn't straightforward to obtain a custom format. So, what I'm looking to do is decouple sectioning from its format. As a workaround, for now, I just want to disable any typesetting of \chapter{...}. In the example below, this means getting rid only of "Chapter 1\nl Fonts", such that "SOME CUST CHAP. FORMAT" comes at the top of the same page.

\documentclass{report}
\usepackage{fontawesome}
\usepackage{lastpage}
\usepackage{tabularx}
\usepackage{titlesec}
\usepackage{titleps}
\usepackage{xparse}

\newcolumntype{R}{>{\raggedleft\arraybackslash}X}
\newcolumntype{C}{>{\centering\arraybackslash}X}

\NewDocumentCommand{\thedoc}
{}% Is there not a command for token list in xparse?
{THIS DOC}

{+mm}
{%
\begin{tabularx}{\textwidth}{@{}XR@{}}#1&#2\end{tabularx}
}
{+mmm}
{%
\begin{tabularx}{\textwidth}{@{}X@{}C@{}R@{}}#1&#2&#3\end{tabularx}
}
\NewDocumentCommand{\chapterMark}{}{UNDEFINED!}
\NewDocumentCommand{\setchapterMark}{m}
{%
\RenewDocumentCommand{\chapterMark}{}{#1}
}
%\setcounter{chapter}{0}
\NewDocumentCommand{\newChapter}{mmO{}}
{%
% \stepcounter{chapter}
\chapter{#1}
\setchapterMark{#2}

SOME CUST CHAP. FORMAT%THAT NO EXISTING PACKAGE CAN EASILY MAKE
\textless#1\textgreater
}
% pagestyle--------------------------------------------------------
\newpagestyle{specialii}
{
\setfoot{%
}{}{}
}
\newpagestyle{specialiii}
{
\setfoot{%
}{}{}
}

\assignpagestyle{\chapter}{specialii}

\begin{document}
\pagestyle{specialiii}
%\pagestyle{empty}
\begin{titlepage}\vspace*{\fill}\huge\begin{center}\thedoc\end{center}\vspace*{\fill}\end{titlepage}

\newChapter{Fonts}{\faFont}

Let's make that span\newpage another page

\end{document}


• What you want is not clear to me. From the image, I'd say maybe you want another formatting for unnumbered chapters like the table of contents index, &c. Could you explain more? – Bernard Oct 7 at 8:21
• I want \chapter to create a chapter, just not display it. That way, I can use whatever functionality is associated with \chapter (in this case \assignpagestyle{\chapter}{specialii}), and customize the display of the chapter. – Erwann Oct 7 at 8:28
• If your special chapter is unnumbered, you can define another formatting and spacing with the numberless key, different from the formatting and spacing for numbered chapters, if it can help. – Bernard Oct 7 at 8:51
• Would I still have to use titleformat? I stated explicitly it was not suitable. – Erwann Oct 7 at 17:22
• I have some difficulty to make out what you want. Must some chapters have only their title, without any label? And must the chapter counter nevertheless be increased? – Bernard Oct 7 at 17:54

Here is a proposition, certainly to be adjusted, as some questions have to be answered: will the chapter title replacement text be a fixed text for all such layouts or will it be just a new chapter title without the label? What about the tableof contents and the header/footer?

 \documentclass{report}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[a6paper, margin=20pt, bottom=34pt, footskip=24pt, showframe]{geometry}
\usepackage{fontawesome5}
\usepackage{lastpage}
\usepackage{lipsum} % Dummy Text
\usepackage[pagestyles, explicit]{titlesec}
\usepackage{xparse, etoolbox}
\usepackage{tabularx}
\usepackage{hyperref}

\renewcommand*\familydefault{\sfdefault}

\NewDocumentCommand{\chapterLabel}{}{Ch. \thechapter}
\NewDocumentCommand{\chapterMark}{}{U HAVE TO DEFINE IT!}
\NewDocumentCommand{\setchapterMark}{m}
{%
\RenewDocumentCommand{\chapterMark}{}{#1}
}%

\newcolumntype{R}{>{\raggedleft\arraybackslash}X}

\newpagestyle{main}{%
\setfoot{\thepage/\pageref{LastPage}}{}{\chapterLabel}
}%

\newpagestyle{special}{%
\setfoot{\thepage/\pageref{LastPage}}{}{\chapterMark}
}%
\newtoggle{nodisplay}

\titleformat{\chapter}{\thispagestyle{empty}\sffamily\large}{\iftoggle{nodisplay}{}{\rlap{\makebox[\textwidth][r]{Ch. \thechapter}}}}{0em}{\iftoggle{nodisplay}{\vspace*{-8.5ex}}{#1}}[\leavevmode\togglefalse{nodisplay}]
\titlespacing*{\chapter}{0pt}{-3ex}{4ex}%-5ex

\pagestyle{main}

\begin{document}

\title{Lorem Ipsum}
\author{Dolor S. Amet}
\maketitle
%
\chapter{Gibberish}
%
\lipsum[1-5]{
\toggletrue{nodisplay}
\chapter{More Gibberish}}
SOME CUSTOM TITLE \par
\lipsum[6-12]
\clearpage

\chapter{Still More Gibberish}
\lipsum[6-12]
\clearpage

\setchapterMark{\faBook}
\pagestyle{special}
\chapter*{Bibliography}
Let's make that
\newpage
... span a second page

\end{document}


• PS: Upon re-flexion it doesn't work. It's going to be hard to give a MWE for what I really want to do. I do know that I don't want \chapter to print absolutely nothing. – Erwann Oct 8 at 3:51

Here's my attempt at adapting @Bernard's answer the MWE of this post:

\documentclass{report}
\usepackage{fontawesome}
\usepackage[showframe]{geometry}
\usepackage{lastpage}
\usepackage{tabularx}
\usepackage[explicit]{titlesec}
\usepackage{titleps}
\usepackage{xparse,etoolbox}

\newcolumntype{R}{>{\raggedleft\arraybackslash}X}
\newcolumntype{C}{>{\centering\arraybackslash}X}

\NewDocumentCommand{\thedoc}
{}% Is there not a command for token list in xparse?
{THIS DOC}

{+mm}
{%
\begin{tabularx}{\textwidth}{@{}XR@{}}#1&#2\end{tabularx}
}
{+mmm}
{%
\begin{tabularx}{\textwidth}{@{}X@{}C@{}R@{}}#1&#2&#3\end{tabularx}
}
\NewDocumentCommand{\chapterMark}{}{UNDEFINED!}
\NewDocumentCommand{\setchapterMark}{m}
{%
\RenewDocumentCommand{\chapterMark}{}{#1}
}
%\setcounter{chapter}{0}
\NewDocumentCommand{\newChapter}{mmO{}}
{%
\setchapterMark{#2}
\chapter{#1}
}
% pagestyle--------------------------------------------------------
\newpagestyle{specialii}
{
\setfoot{%
}{}{}
}
\newpagestyle{specialiii}
{
\setfoot{%
}{}{}
}

\newtoggle{nodisplay}

\titleformat{\chapter}
{
\thispagestyle{specialii}
\sffamily\large
}
{
\iftoggle{nodisplay}
{}
{
}
}
{0em}
{
\iftoggle{nodisplay}
{
%\vspace*{-8.5ex}
}
{SOME CUST CHAP. FORMAT%THAT NO EXISTING PACKAGE CAN EASILY MAKE
\textless#1\textgreater}
}[\leavevmode\togglefalse{nodisplay}]

\titlespacing*{\chapter}{0pt}{-3ex}{0ex}%-5ex

\begin{document}
\pagestyle{specialiii}
\begin{titlepage}\vspace*{\fill}\huge\begin{center}\thedoc\end{center}\vspace*{\fill}\end{titlepage}

\newChapter{Fonts}{\faFont}

Let's make that span\newpage another page

\end{document}


Here's an answer that is closer to the problem specification as it disables the display of the chapter header, and that only. I gave an example here in which customizing chapter header through titleformat probably not doable. I added the toc to show it is unaffected. A few cosmetic TODO's remain within the code...

\documentclass{report}
\usepackage[french]{babel} % added to problem specification
\usepackage{fontawesome}
\usepackage[showframe]{geometry}
\usepackage{lastpage}
\usepackage{tabularx}
\usepackage{titleps}
\usepackage{xparse}
\usepackage{xpatch}

%https://tex.stackexchange.com/questions/511253/how-can-i-keep-sectioning-but-disable-its-display

%disabling chapter display----------------------------------------
% This one does:
\usepackage{xpatch}
\tracingpatches
\makeatletter % the macro name contains @
\patchcmd{\@chapter}{\if@twocolumn
\else
\fi}{}{}{}
\makeatother

%-----------------------------------------------------------------
\newcolumntype{R}{>{\raggedleft\arraybackslash}X}
\newcolumntype{C}{>{\centering\arraybackslash}X}
\NewDocumentCommand{\thisdoc}
{}% TODO Is there not a command for token list in xparse?
{THIS DOC}

{+mm}
{%
\begin{tabularx}{\textwidth}{@{}XR@{}}#1&#2\end{tabularx}
}
{+mmm}
{%
\begin{tabularx}{\textwidth}{@{}X@{}C@{}R@{}}#1&#2&#3\end{tabularx}
}
\NewDocumentCommand{\chapterMark}{}{UNDEFINED!}
\NewDocumentCommand{\setchapterMark}{m}
{%
\RenewDocumentCommand{\chapterMark}{}{#1}
}
\NewDocumentCommand{\newChapter}{mmO{}}
{%
\setchapterMark{#2}
\chapter{#1}
\thispagestyle{specialii}
{SOME CUST CHAP. FORMAT%THAT NO EXISTING PACKAGE CAN EASILY MAKE
\textless#1\textgreater}
}

%-----------------------------------------------------------------
\newpagestyle{specialii}
{
\setfoot{%
}{}{}
}
\newpagestyle{specialiii}
{
\setfoot{%
}{}{}
}

\begin{document}%-------------------------------------------------
\thispagestyle{empty}
\begin{titlepage}\vspace*{\fill}\huge\begin{center}\thisdoc\end{center}\vspace*{\fill}\end{titlepage}
\tableofcontents
\pagestyle{specialiii}
\newChapter{Writing}{\faPencil}

Let's make that span\newpage another page

\newChapter{Fonts}{\faFont}

Fonts are great.

\end{document}


EDIT on 10/10:

• Replaced the crude modification on internals of \chapter with one using \patchcmd.

• Added \usepackage[french]{babel}, which causes problems (french added to the chapter title), hence