If you need to maintain MacPorts releated files which should not be distributed widely you can setup a personal space inside the MacPorts Subversion repository. You do this using the Terminal with the following command.

Repository=http://svn.macosforge.org/repository/macports
User=userid

svn mkdir --username ${User}@macports.org -m"Create user repository for ${User}" ${Repository}/users/${User}
svn checkout ${Repository}/users/${User} macports-${User}

Use your MacPorts user for userid