Ok. I do not know how stored in a snippet this structure:

$tar -tvf pkg-groups.tar
drwxr-xr-x root/root         0 2013-09-06 10:45 groups/
-rw-r--r-- 598/599         245 2010-08-23 13:07 groups/dhcp-server-a.directory
-rw-r--r-- 598/599         207 2010-08-23 13:07 groups/centaurus-gnome.directory
-rw-r--r-- 598/599         196 2010-08-23 13:07 groups/buildsystem.directory
...
drwxr-xr-x root/root         0 2013-09-06 21:29 lists/
-rw-r--r-- 598/599           6 2011-04-12 11:29 lists/gnome-phone
-rw-r--r-- 598/599          10 2011-04-12 11:29 lists/eclipse
-rw-r--r-- 598/599         123 2011-04-12 11:29 lists/gnome-office
...

any ideas?