Documentation in this directory has already been formatted with nroff.
While the sources are available, some are written with -mm and some
with -ms.  Since USG systems have only -mm and V7 and 4BSD has only -ms,
about the only portable way to write documents is to use the -man macros.
(No thanks!)  To make the documents usable to everyone, they are distributed
pre-formatted.  Overstriking is done with carriage return (rather than
backspace) which seems to work better on some line printers.