Section title with as subtitle as the title for tcolorbox?

Question

To get a section title with a subtitle (where I also do not want the subtitle to show up in the table of contents) I've been using something like:

\section[Title]{Title\\ \footnotesize{Subtitle}}

But using this as a title for a tcolorbox produces numerous errors, the following does not work:

\begin{tcolorbox}[title=\section[Title]{Title\\ \foonotesize{Subtitle}}]

What would be the way to get something functionally equivalent to the above to work?

Answer 1

If the subtitle should anyway not be in the toc, you don't need them inside the section title and can put them after it:

\documentclass{article}
\usepackage[most]{tcolorbox}

\begin{document}

\tableofcontents


\begin{tcolorbox}[title={\protect\section[Title]{Title}\footnotesize subtitle}]

test

\end{tcolorbox}


\end{document}