code: public static boolean isXML11ValidLiteral(int c) {
          return ((c < 0x10000 && ((XML11CHARS[c] & MASK_XML11_VALID) != 0 && (XML11CHARS[c] & MASK_XML11_CONTROL) == 0))
              || (0x10000 <= c && c <= 0x10FFFF)); 
      }
docs: Returns true if the specified character is valid and permitted outside
  of a character reference.
  That is, this method will return false for the same set as
  isXML11Valid, except it also reports false for "control characters".
  
  @param c The character to check.