e called literal markers.  They are
   copied exactly as they appear in pictur into the output string.
   The recognized parts of the picture are replaced by a
   component of time or, as in the case of `::TDB' are used
   as instructions about the overall properties of the time
   string.

   The full list of recognized markers, their classification
   and meaning are given below.

   MARKER       CLASS     MEANING
   -----------  --------  -----------------------------------------
   &quot;.##...&quot;   