title: What do the abbreviations in POS tagging etc mean?
body: <p>Say I have the following Penn Tree:</p>
  
  <pre><code>(S (NP-SBJ the steel strike)
   (VP lasted
       (ADVP-TMP (ADVP much longer)
                 (SBAR than
                       (S (NP-SBJ he)
                          (VP anticipated
                              (SBAR *?*))))))
   .)
  </code></pre>
  
  <p>What do abbrevations like <code>VP</code> and <code>SBAR</code> etc mean? Where can I find these definitions? What are these abbreviations called?</p>