Checking out a single port

[Roop Nanuwa]

Hello,
       On my firewall/gateway I have very limited disk space so I can't 
afford to have the entire
ports tree checked out. I would like to be able to check out the 
skeleton for a single port
so I can install just that when need be (I do have the base required 
files for the ports tree
installed). Problem is that it seems that using CVSup, I can only update 
a particular ports
directory (i.e. ports-security) not particular ports.

As an example, say I want to install OpenBSD's pf that's been ported to 
FreeBSD. Can I
get the files in
/usr/ports/securty/pf
without having to get all the files in other directories of 
/usr/ports/security as well?

Just to save some time with responses that I know will come:
- I want to install from source so binary packages from pkg_add is not a 
(wanted) choice
- I know that the compile will choke if I'm missing the ports info for 
the required dependencies.

Thanks.