optional_depends "libusb-compat" "--enable-libusb"    "--disable-libusb"    "for usb support"
optional_depends "bluez"         "--enable-bluetooth" "--disable-bluetooth" "for bluetooth support"
optional_depends "libical"       "--enable-libical"   "--disable-libical"   "for ical support"
optional_depends "mysql"         "--enable-mysql"     "--disable-mysql"     "for mysql database support"
optional_depends "postgresql"    "--enable-postgres"  "--disable-postgres"  "for postgresql database support"
optional_depends "gtk+-2"        "--with-x"           "--without-x"         "for a graphical frontend"
