Bdtyktl

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?

You can use the text fonts or images

documentclass{article}

usepackage{graphicx}



begin{document}



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



end{document}

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}



[

qmquadmathrm{qm}quad

mathit{qm}quadmathsf{qm}quad

mathtt{qm}quadmathbbold{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.