track.
The $Id$ line is normally at the bottom of the main comment block in the
man page, separated from the rest of the manpage by an empty comment,
like so;
.\" $Id$
.\"
If the immediately preceding comment is a @(#) format ID marker than the
the $Id$ will line up underneath it with no intervening blank lines.
Otherwise, an additional blank line is inserted.
Approved by: bde
DANGER WILL ROBINSON!
_PATH_UNIX is currently defined as the literal string "don't use this".
I am of two minds about this myself, but wanted to get something into the
tree as quickly as possible.