15.64.31.22  Lexicals   - When a histogram is set S_HIST_NAME contains the
the current histogram name.

If  the  histogram package has limits or markers set on the histogram they
are put into V_XMARKER[n] and V_YMARKER[n].  HBOOK has  no  markers.   The
number of markers is limited to n=8.  The lexicals are set to a very large
number 1.0E+30 if they do not contain markers.