title: What does this "a file local variable" mean?
body: <p>I am reading about the <code>kill-emacs-hook</code> variable in the emacs manual.
  It says:</p>
  
  <blockquote>
    <p><code>kill-emacs-hook</code> is a variable defined in `C source code'.<br>
    Its value is<br>
    <code>(org-babel-remove-temporary-directory migemo-pattern-alist-save)</code></p>
    
    <p>This variable is potentially risky when used as a file local variable.  </p>
    
    <p>Documentation:<br>
    Hook to be run when &#96;<code>kill-emacs</code>' is called.<br>
    ...abbr...</p>
  </blockquote>
  
  <p>I do not understand this sentence: "a file local variable". What does this "a file local variable" mean?</p>