Here are some numeric character references outside MathJax (entered as ♯ + ♭ = ♮
):
♯ + ♭ = ♮
and inside MathJax ($♯ + ♭ = ♮$
):
$♯ + ♭ = ♮$
The latter renders properly in the preview, but is broken once I save. This makes my suggestion for using curly quotes not work.
:)
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