File permissions can be set independent of the permissions of the source files. The default policy for swign is to use the current owner and group. For reasons explained later, setting the ownerships to 0/0 for the owner and group is helpful. This is done with the following line in the PSF.
file_permissions -o 0 -g 0
The resulting ownerships are equivalent to the GNU tar options
--numeric --owner=root --group=root
.