“ MediaWiki templates, variables and parameters cannot be used within math tags, see Demo of attempt to use parameters within TeX.
The PNG images are black on white (not transparent) . These colors, as well as font sizes and types, are independent of browser settings or css. Font sizes and types will often deviate from what HTML renders. The css selector of the images is img.tex.
In the case of a non-white page background, the white background of the formula effectively highlights it, which can be an advantage or a disadvantage. ”

“ Fractions can also be made with the TeX, but they do not match the Mediawiki typeface.
Functions Functions are rendered in Mediawiki by a version of TeX. The following text is from Meta-Wiki.
TeX w:MediaWiki uses a subset of TeX markup for mathematical formulae. See meta:MediaWiki math markup
It generates either PNG images or simple HTML markup, depending on user preferences and the complexity of the expression. In the future, as more browsers are smarter, it will be able to generate enhanced HTML or even MathML in many cases. ”

“ For example, fractions can be made smaller using
frac instead of \frac.
becomes .
In general, formulas can be made even smaller if \scriptstyle is employed:
becomes .
Functions, symbols, special characters For producing special characters without math tags, see m:Help:Special characters.
Comparison:
α gives "α" $\backslash alpha$ gives , ("&" and ";" vs. "\<", in this case the same code word "alpha") ; √2 gives "√2" $\backslash sqrt\{2\}$ gives (the same difference as above, but also another code word, "radic" vs. "sqrt"; in TeX braces) ”