title: HTML5: Where is the spec for which end tags are forbidden?
body: <p>In HTML 4.01 certain end tags are <strong><em>forbidden</em></strong>, that means it in not valid markup to have them, e.g.:</p>
  
  <pre><code>Invalid                     Valid
  ===================         =================
  &lt;BR/&gt;                       &lt;BR&gt;
  &lt;BR&gt;&lt;/BR&gt;      
  
  &lt;IMG src="..."/&gt;            &lt;IMG src="..."&gt;
  &lt;IMG ...&gt;&lt;/IMG&gt;
  
  &lt;INPUT ... /&gt;               &lt;INPUT ...&gt;
  &lt;INPUT ...&gt;&lt;/INPUT&gt;
  </code></pre>
  
  <p>In the HTML 4.01 specification the indication of an end tag being <em>optional</em> or <em>forbidden</em> is nicely summarized in <a href="http://www.w3.org/TR/html4/index/elements.html" rel="noreferrer">the index of elements</a>:</p>
  
  <pre><code>Name        Start Tag       End Tag
  AREA                        F
  BASE                        F
  BASEFONT                    F
  BODY        O               O
  BR                          F
  COL                         F
  COLGROUP                    O
  DD                          O
  DT                          O
  FRAME                       F
  HEAD        O               O
  HR                          F
  HTML        O               O
  IMG                         F
  INPUT                       F
  ISINDEX                     F
  LI                          O
  LINK                        F
  META                        F
  OPTION                      O
  P                           O
  PARAM                       F
  TBODY       O               O
  TD                          O
  TFOOT                       O
  TH                          O
  THEAD                       O
  TR                          O
  </code></pre>
  
  <p>Where is the HTML 5 equivalent of indicating which end tags are:</p>
  
  <ul>
  <li>required</li>
  <li>optional (implicit)</li>
  <li>forbidden</li>
  </ul>