Note that apt-0.5.15cnc6 includes a more generic allow-duplicated script in contrib/. Unfortunately that doesn't work well with RHL/RHEL/FC distributions due to the way RH packages their kernels whereas this works around that fact. Apart from just handling allow-duplicated packages more transparently this script also does fancy stuff like automatically updating kernel-module packages and setting default bootloader so it's not 1:1laiskiainen.orgparable with the allow-duplicated script from contrib.