The nroff script emulates the nroff command using groff. Only ascii, latin1, koi8-r, utf8, and cp1047 are valid arguments for the -T option, selecting the output encoding emitted by grotty, groffs TTY output device. If an invalid or no -T option is given, nroff checks the current locale to select a default output device. It first tries the locale program, then the environment variables LC_ALL, LC_CTYPE, and LANG, and finally the LESSCHARSET environment variable.
The -h and -c options are equivalent to grottys options -h (using tabs in the output) and -c (using the old output scheme instead of SGR escape sequences). The -d, -C, -i, -m, -n, -o, and -r options have the effect described in troff(1). In addition, nroff silently ignores the options -e, -q, and -s (which are not implemented in troff). Options -p (pic), -t (tbl), -S (safer), and -U (unsafe) are passed to groff. -v shows the version number.