> When you say points are '(about 1/72")', it probably > doesn't hurt to go the extra mile (!) in precision and > say '(1/72.27")'. It's shorter (no need for 'about') > and more correct.
Historically, the size of the point varied from region to region. TeX uses 1/72.27 inches for its point, but as far as I know, groff uses the Postscript point, which is 1/72 inches exactly.
