All macro file names must be named name.tmac or
tmac.name to make the -mname command-line
option work. The mso request doesn’t have this restriction; any
file name can be used, and gtroff won’t try to append or prepend
the ‘tmac’ string.
Macro files are kept in the tmac directories, all of which constitute the tmac path. The elements of the search path for macro files are (in that order):
gtroff’s or groff’s
-M command-line option.
GROFF_TMAC_PATH environment variable.
/usr/local/lib/groff/site-tmac /usr/local/share/groff/site-tmac /usr/local/share/groff/1.23.0/tmac
assuming that the version of groff is 1.23.0, and the
installation prefix was /usr/local. It is possible to fine-tune
those directories during the installation process.