The command certainly does not work, and I cannot find the section of the man page you have provided in the man page on my system or the online man page:
http://www.freebsd.org/cgi/man.cgi?q...SE&format=html
If you are seeing this in your man page then I can only assume we are using different FreeBSD versions, here is the out put from
uname -a:
FreeBSD 7.0-RELEASE-p1