 <p>The macros <code>\textup</code>, <code>\AE</code>, and <code>\SS</code> are not part of the default MathJax TeX macros and are not defined in your inline configuration, which is why the rendering in the image has them marked in red. </p> <p>You'll see a more specific error if you remove the <code>noundefined</code> and <code>noerrors</code> extensions from your configuration -- which are also in <a href="http://docs.mathjax.org/en/latest/config-files.html#the-tex-ams-html-configuration-file" rel="nofollow">the combined configuration <code>TeX-AMS_HTML</code></a>, so you'll need to drop that as well; as you can see from the link, your inline configuration entails all of <code>TeX-AMS_HTML</code>. (In production, it's preferable to use a combined configuration file since they load as a single large file.)</p> <p>For a list of all default MathJax macros, see <a href="http://docs.mathjax.org/en/latest/tex.html#supported-latex-commands" rel="nofollow">http://docs.mathjax.org/en/latest/tex.html#supported-latex-commands</a>.</p> <p>For how to define macros in MathJax, see <a href="http://tex.stackexchange.com/questions/139699/equivalent-of-mathup-for-upright-text-in-math-mode">http://tex.stackexchange.com/questions/139699/equivalent-of-mathup-for-upright-text-in-math-mode</a>. From there an example:</p> <pre><code>MathJax.Hub.Config({ TeX: { Macros: { RR: "{\\bf R}", bold: ["{\\bf #1}",1] } } }); </code></pre> <p>i.e., add a <code>Macros</code> block to the <code>TeX</code> block in your configuration.</p> <p>(A particular case is<code>\textup</code>, which is a LaTeX <em>text mode</em> macro and MathJax focuses on <em>math mode</em>. Depending on the use case, the math equivalent might be <code>\text{}</code>, <code>\mathrm{}</code>, or something else, see <a href="http://tex.stackexchange.com/questions/139699/equivalent-of-mathup-for-upright-text-in-math-mode">this TeX.SE questions</a>. Of course you can define <code>\textup</code> to be whatever you like but you might run into trouble backporting content to real TeX).</p>