15.64.34  LABELS 

This sets the size and enables  the  numeric  labels  on  each  axis.   To
control the default number of ticks see SET SCALE.
SET LABELS [SIZE=n] [CHARACTERS=n] [INSIDE[=ON|OFF] [ALL|TOP|BOTTOM|RIGHT|
          LEFT|X|Y|Z] [ON|OFF] [SHIFT=n]
     [INTENSITY|WIDTH=n]
     [NOCOLOR|WHITE|RED|GREEN|BLUE|YELLOW|MAGENTA|CYAN]
     [PERMANENT]
This  acts  on  the  current plot only if PERMANENT not specified.  If the
parameters are omitted they are reset to the original default.  To control
other individual elements of the axes use:
SET AXES, SET TICKS, SET OUTLINE, SET SCALES

(DEFAULT:LEFT ON,BOTTOM ON)