HIGH-VALUE HIGH-VALUES *> Equivalent to (a string of) X"FF".
LOW-VALUE  LOW-VALUES  *>  "                       "  X"00".
NULL                   *>  "                       "  X"00".
QUOTE      QUOTES      *>  "                       "  double-quote character.
SPACE      SPACES      *>  "                       "  space.
ZERO   ZEROS   ZEROES  *>  "                       "  zero.