title: Where is #{resource} EL specified?
body: <p>In a JSF page, I use EL to locate an image which placed in <code>/resource/images/</code> folder.</p>
  
  <pre><code>&lt;h:graphicImage value="#{resource['images:logo.gif']}"
  </code></pre>
  
  <p>How can EL locate the image?
  Maybe a specification defines the rule, but I don't know which specification.
  I try to find it in the <a href="https://www.jcp.org/en/jsr/detail?id=344" rel="nofollow">JSR-000344 JavaServer Faces 2.2</a> ，the <a href="https://www.jcp.org/en/jsr/detail?id=342" rel="nofollow">JSR-000342 Java Platform, Enterprise Edition 7</a>, the <a href="https://www.jcp.org/en/jsr/detail?id=341" rel="nofollow">JSR-000341 Expression Language 3.0</a>, but not found.</p>