title: Content-Disposition Special Characters
body: <p>I have encountered an issue when trying to serve files with spanish tildes, related to the Content-Disposition encoding.</p>
  
  <p>The file name is "qué hacés ahora.docx"</p>
  
  <p>So far, the ASP.NET MVC way of serving files adds this header, which works fine only in Firefox:</p>
  
  <pre><code>Content-Disposition: attachment; filename*=UTF-8''qu%C3%A9%20hac%C3%A9s%20ahora.docx
  </code></pre>
  
  <p>I am using in the controller:</p>
  
  <pre><code>return File(path, "application/octet-stream", originalNameWithAccents);
  </code></pre>
  
  <p>This is not working in IE or Chrome.</p>
  
  <p>So, I went and emailed myself the file as an attachment using GMail. Using firebug to see what is going on, the Content-Disposition google is sending back down is:</p>
  
  <pre><code>Content-Disposition: attachment; filename="=?UTF-8?B?cXXDqSBoYWPDqXMgYWhvcmEuZG9jeA==?="
  </code></pre>
  
  <p>Notice how the name is base64 encoded (cXXDqSBoYWPDqXMgYWhvcmEuZG9jeA==).</p>
  
  <p>So, I have 2 questions so far:</p>
  
  <ol>
  <li>Where is an specification for this?</li>
  <li>Are there any known ways of serving this type filename using ASP.NET?</li>
  </ol>