Table 1. GROFF Units
INDICATOR NAME CLASS* UNIT VALUE
i inch abs 1 inch
c centimeter abs 1 centimeter
p point abs 1/72 inch
P pica abs 1/6 inch (12 points)
m em rel current font size in points
n en rel 1/2 em
M emette rel 1/100th of an em
v leading rel current vertical spacing in points
u basic unit dev device resolution [1/72000 inch]
z sizescale dev basic units per point [1000]
Notes:
* Scale units are classified according to whether the
unit represents an absolute unit of measure, is relative
to the current pointsize/leading or is device dependent
(values in brackets are applicable for PostScript devices).
** A groff extension (as is the <\#147>z<\#148> unit); the name
given here is contrived by the author.