title: ExpiresActive On .htaccess explanation
body: <pre><code>[i]ExpiresActive On
  ExpiresByType image/gif A2592000
  ExpiresByType image/jpeg A2592000
  ExpiresByType image/png A2592000
  BrowserMatch "MSIE" brokenvary=1
  BrowserMatch "Mozilla/4.[0-9]{2}" brokenvary=1
  BrowserMatch "Opera" !brokenvary
  SetEnvIf brokenvary 1 force-no-vary[/i]
  </code></pre>
  
  <p>saw this code in a sample .htaccess recently.</p>
  
  <p>Presumably ExpiresByType sets an expiry time on images - is that related to the visitors browser cache? and what does <strong>A2592000</strong> translate to?</p>
  
  <p>and what does the "brokenvary=1" imply? I gather it's looking for a UserAgent, but then what?</p>
  
  <p>thanks!</p>