Macro Directories (The GNU Troff Manual)

### 2.3 Macro Directories

A macro file must have a name in the form `name.tmac` or `tmac.name` and be placed in a tmac directory to be found by the `-mname` command-line option.5 Together, these directories constitute the tmac path. Each directory is searched in the following order until the desired macro file is found or the list is exhausted.

- Directories specified with GNU `troff`’s or `groff`’s `-M` command-line option.
- Directories listed in the `GROFF_TMAC_PATH` environment variable.
- The current working directory (only if in unsafe mode using the `-U` command-line option).
- The user’s home directory, `HOME`.
- A platform-dependent directory, a site-local (platform-independent) directory, and the main tmac directory. The locations corresponding to your installation are listed in section “Environment” of gtroff(1). If not otherwise configured, they are as follows.

      /usr/local/lib/groff/site-tmac
      /usr/local/share/groff/site-tmac
      /usr/local/share/groff/1.23.0/tmac

  The foregoing assumes that the version of `groff` is 1.23.0, and that the installation prefix was `/usr/local`. It is possible to fine-tune these locations during the source configuration process.