title: How to allow custom uppercase tags in TinyMCE
body: <p>Does anyone know how to allow having custom uppercase tags in TinyMCE?  It seems that TinyMCE doesn't like uppercase tags, even though they have been declared as valid.  Here is my TinyMCE config:</p>
  
  <pre><code>tinyMCE.init({
      mode: "specific_textareas",
      theme: "advanced",
      language: "en",
      theme_advanced_toolbar_location: "top",
      theme_advanced_toolbar_align: "left",
      theme_advanced_statusbar_location: "bottom",
      theme_advanced_buttons1: "bold,italic,|,sub,sup,|,charmap,|,table,|,code",
      theme_advanced_path: false,
      theme_advanced_resizing: true,
      plugins: "fullscreen,paste,table",
      paste_auto_cleanup_on_paste : true,
      relative_urls: false,
      width: "300",
      height: "300",
      theme_advanced_resizing_min_height : "10",
      force_br_newlines : true,
      force_p_newlines : false,
      forced_root_block : '',
      entity_encoding: "raw",
      valid_elements : "B/strong,I/em,SUP/sup,SUB/sub",
      extended_valid_elements: "CUSTOM"
  })
  </code></pre>
  
  <p>Typing something like</p>
  
  <pre><code>&lt;CUSTOM&gt;this is a custom tag&lt;/CUSTOM&gt;
  </code></pre>
  
  <p>doesn't work because &lt;CUSTOM> gets stripped off.</p>
  
  <p>If I change the init script to <code>extended_valid_elements: "custom"</code>, then it works fine - I can type</p>
  
  <pre><code>&lt;custom&gt;this is a custom tag&lt;/custom&gt;
  </code></pre>
  
  <p>and the &lt;custom gets preserved.</p>
  
  <p>Doesn't anyone know any workaround?</p>
  
  <p>Thanks!</p>