# “Different” looking question mark

I'm in a situation where I have a concept in my document that is traditionally represented using the question mark ?.

However, for visual clarity, I would like to differentiate between the ordinary punctuation ?, and my "special" use of it as a symbol.

I have tried mathbb, mathcal, and most of the other typical math font modes, but all of them seem to render ? in an identical way (at least under the default options of the acmart class).

Is there some way that I can get a fancy ? symbol? Bold, italic, black board, calligraphy, I'm open to different options. The inverted question mark is not an option, as it already carries meaning in my particular field.

EDIT:

For reference, if I do this:

\documentclass{article}
\usepackage{amsmath}
\usepackage{amssymb}
\begin{document}
$\mathsf{?} ? \mathbf{?} \mathit{?} \mathbb{?} \mathcal{?}$
\end{document}


It renders as this: i.e. there is no difference between the symbols.

The font used is Libertine, specifically the Libertine option of newtxmath, maybe this is part of the problem?

• This is a bit vague. – egreg Dec 3 '18 at 22:39
• @DavidCarlisle Yes, this is in math. I've updated to question to clarify that mathbf and mathit seem to do nothing. – jmite Dec 3 '18 at 22:43
• @DavidCarlisle: exact same results on overleaf with a minimal complete document (question updated to include self-contained example) – jmite Dec 3 '18 at 22:52
• @jmite yes well my initial comment was not as accurate as it could have been:-) – David Carlisle Dec 3 '18 at 22:55

You can use the text fonts or images

\documentclass{article}
\usepackage{graphicx}

\begin{document}

$?\,\textbf{?}\,\textit{?}\,\textsf{?}\,\includegraphics[height=.7em]{q}$

\end{document}

• @jmite do you want to buy that original mspaint artwork brushstroke? :-) – David Carlisle Dec 3 '18 at 23:14

The behavior of the character ? in math is defined by

\DeclareMathSymbol{?}{\mathclose}{operators}{"3F}


so it isn't affected by math alphabet changing commands such as \mathsf. You can define

\DeclareMathSymbol{\qm}{\mathalpha}{operators}{"3F}


Example:

\documentclass{article}
\usepackage{amsmath} % not really used here

\DeclareMathSymbol{\qm}{\mathalpha}{operators}{"3F}
\DeclareMathAlphabet{\mathbbold}{U}{bbold}{m}{n}

\begin{document}

$\qm\quad\mathrm{\qm}\quad \mathit{\qm}\quad\mathsf{\qm}\quad \mathtt{\qm}\quad\mathbbold{\qm}$

\end{document}


A different approach: find a font that has the glyph that suits your need and do something like

\documentclass{article}
\usepackage{amsmath}

\newcommand{\qm}{\text{\usefont{OT1}{iwona}{m}{n}?}}

\begin{document}

$\qm$

\end{document}


Differently from using \textbf or \textit, both approaches will not be affected by the font current at the time math mode was entered. For instance, in a theorem statement, typically using italics, $\textbf{?}$ would be typeset in boldface italic.