title: Compiler Warning CS1591 "Missing XML Comment" isn't showing and I want it to
body: <p>I've searched and only found questions from people who want to suppress this warning such as <a href="https://stackoverflow.com/questions/7982525/visual-studio-disabling-missing-xml-comment-warning">Visual Studio Disabling Missing XML Comment Warning</a>, or how to show it for only certain types of member, or how to add it to private members.</p>
  
  <p>However for me this warning has never shown, in any of my copies of Visual Studio... and I want it to. I didn't even know the warning existed until today. I like to document my code, and want to know I've not missed any places.</p>
  
  <p>Using the link above I've gone through the suggestions for disabling it in the accepted answer and checked none of those have already been done without my knowledge or without me remembering.</p>
  
  <p>However this is happening (or not happening) in all copies of Visual Studio I have used in recent years, VS2013 Pro and VS2013 Express and VS2015 Community. And is the same across many projects, including ones I started myself from scratch and ones I have inherited from other developers.</p>
  
  <p>Is there something I need to do to enable it in these versions? I'm confused as to why I'm not seeing it.</p>