title: React 16 HTML attributes with MathML tags
body: <p>I'm using MathML markup language to render math equations on my web app. Here's an example of an simple equation which is problematic:</p>
  
  <pre><code>&lt;math xmlns="http://www.w3.org/1998/Math/MathML"&gt;&lt;mfenced open="[" close="]"&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/mfenced&gt;&lt;/math&gt;
  </code></pre>
  
  <p>The problem is that React will not treat the attributes of the mfenced tag like we would want to. It treats the "<a href="https://www.w3schools.com/tags/att_open.asp" rel="nofollow noreferrer">open</a>" attribute as if it was used in a HTML context, so it will not accept its "[" value. React will output the mfenced tag like this:</p>
  
  <pre><code>&lt;mfenced open close="]"&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/mfenced&gt;
  </code></pre>
  
  <p>Of course, this breaks the equation in the browser. Is there a way to tell React not to change this attribute?</p>