title: What's wrong with my RewriteRule via .htaccess? (Why does it need RewriteBase?)
body: <pre><code>rewriteengine on
  rewriterule ^/a/b$ ^/c$
  </code></pre>
  
  <p>not working,but </p>
  
  <pre><code>rewriteengine on
  rewritebase /
  rewriterule ^a/b$ ^c$
  </code></pre>
  
  <p>works.</p>