mjhjmtu

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:

documentclassarticle
usepackageamsmath
usepackageamssymb
begindocument
$mathsf? ? mathbf? mathit? mathbb? mathcal?$
enddocument

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

documentclassarticle
usepackagegraphicx

begindocument

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

enddocument

The behavior of the character ? in math is defined by

DeclareMathSymbol?mathcloseoperators"3F

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

DeclareMathSymbolqmmathalphaoperators"3F

Example:

documentclassarticle
usepackageamsmath % not really used here

DeclareMathSymbolqmmathalphaoperators"3F
DeclareMathAlphabetmathbboldUbboldmn

begindocument

[
qmquadmathrmqmquad
mathitqmquadmathsfqmquad
mathttqmquadmathbboldqm
]

enddocument

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

documentclassarticle
usepackageamsmath

newcommandqmtextusefontOT1iwonamn?

begindocument

[
qm
]

enddocument

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.