title: Which object properties are not allowed in a JS object in IE?
body: <p>A few months ago I discovered through great pain that you cannot do this in IE:</p>
  
  <pre><code>{class:'bacon'}
  </code></pre>
  
  <p>Because "class" is a reserved word. Today I discovered that <code>export</code> is also a reserved word in IE. As I understand it, reserved or not, they <em>should</em> be valid within this context. I'm having trouble finding any documentation on this though.</p>
  
  <p>What keywords are invalid to use as unquoted property names in Internet Explorer (or other browsers if they too impose restrictions)?</p>