If you customised a language pack xx, the only folder you need to back up is $CFG->dataroot/lang/xx_local. All others without the _local suffix are standard packages that can be installed and uninstalled via the admin tool.
If you customised a language pack xx, the only folder you need to back up is $CFG->dataroot/lang/xx_local. All others without the _local suffix are standard packages that can be installed and uninstalled via the admin tool.