code: function processProtectedElement( that, comment, protectedRegexs, filterOpts ) {
  		var source = decodeURIComponent( comment.value.replace( /^\{cke_protected\}/, '' ) ),
  			protectedFrag,
  			toBeRemoved = [],
  			node, i, match;
  
  		// Protected element's and protected source's comments look exactly the same.
  		// Check if what we have isn't a protected source instead of protected script/noscript.
  		if ( protectedRegexs ) {
  			for ( i = 0; i < protectedRegexs.length; ++i ) {
  				if ( ( match = source.match( protectedRegexs[ i ] ) ) &&
  					match[ 0 ].length == source.length	// Check whether this pattern matches entire source
  														// to avoid '<script>alert("<? 1 ?>")</script>' matching
  														// the PHP's protectedSource regexp.
  				)
  					return true;
  			}
  		}
  
  		protectedFrag = CKEDITOR.htmlParser.fragment.fromHtml( source );
  
  		if ( protectedFrag.children.length == 1 && ( node = protectedFrag.children[ 0 ] ).type == CKEDITOR.NODE_ELEMENT )
  			processElement( that, node, toBeRemoved, filterOpts );
  
  		// If protected element has been marked to be removed, return 'false' - comment was rejected.
  		return !toBeRemoved.length;
  	}
docs: Filter element protected with a comment. Returns true if protected content is ok, false otherwise.