title: Is the at-sign (@) a valid HTML/XML tag character?
body: <p>I'm doing some HTML stripping using regular expressions (yes, I know, never <em>parse</em> HTML with regexes, but I'm just <em>stripping</em> it, and I also unfortunately cannot use any external libraries).  I'm using a regex from the Regular Expressions Cookbook, and it has worked great, except I just ran into this problem:</p>
  
  <p>In the string <code>Bob Saget &lt;bobs@aol.com&gt;</code>, my regex is matching the email as a tag.</p>
  
  <p>So my question is, is the <code>@</code> sign a valid XML or HTML <strong>tag</strong> character?  (I'm not asking whether or not it is valid within an attribute; I know that it is)  If it is not, I will be able to successfully exclude it in my regex.</p>
  
  <p>I'm not sure where to look this up.  I looked <a href="http://www.w3.org/TR/2000/REC-xml-20001006#NT-NameChar" rel="noreferrer">here</a> and I think that says that in XML, the at-sign is not allowed in a tag; however, I would appreciate some concrete proof.</p>