post_install() {
  cat << EOF

NOTE
----
# If you want to use this driver with sane:
#  echo "hpaio" >> /etc/sane.d/dll.conf

EOF
}

post_upgrade() {
  if [ "`vercmp $2 3.12.4-2`" -lt 0 ]; then
    # important upgrade notice
    echo "> Please remove your printer in cups, then add it"
    echo "> back and reconfigure it to make it work again!"
  fi
}