Documented in Volume 1 of the UNIX Programmers Manual.
See /usr/doc/tbl on 4.2 BSD systems for additional online documentation on this.
% tbl filename | nroff -ms > filename.n
runs tbl on filename, pipes output to nroff and redirect
output to filename.n
% tbl filename | neqn | nroff
runs tbl on filename, pipes result to neqn, then pipes output
to nroff.
From: wa371@sdcc12.UUCP (wa371) Path: bass!sdcsvax!sdcc3!sdcc12!wa371
Subject: How to view the output of a boxed table on a crt or line printer:
I recently asked for help in viewing the output of tbl(1) on a crt or line
printer. My difficulty was that vertical lines of a boxed table were being
printed AFTER the rest of the table. Additionally a flock of control
characters were giving my terminal hiccups.
After experimenting with various suggestions I found that the following
command seems to give the cleanest results (under 4.2bsd):
% tbl filename | nroff -ms | colcrt | more
See also soelim if you are using embedded .so lines.