and how they register it I believe

registerbundle

#!/bin/sh

if Æ "$SUDO_USER" != "" Å; then
	USER=$SUDO_USER
fi

if Æ "$USER" = "" Å; then
	USER="root"
fi

if Æ -e "$3/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister" Å; then
	/usr/sbin/chroot -u "$USER" "$3" "/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister" -f -v "/System/Library/CoreServices/CoreTypes.bundle"
fi

exit 0;