Zabbix User Interface (UI) uses GNU gettext.
The language becomes enabled in Zabbix frontend when it is at least 50% translated.
In general, UI translations are much simpler than those for documentation, but here are some things that you have to be mindful of:
<percent symbol> <number> <dollar sign><”s” symbol>
If a string has tabs, it is important to add a translation for each tab. Otherwise, an incomplete translation will return an error during import to Zabbix and will have to be deleted.
There are also other things to look out for, but these two in particular have caused the most problems in the past.
During Zabbix release procedure translation errors are checked for, and if any are encountered, the release process cannot continue. If errors occur in a language that Zabbix team speaks, then we will attempt to fix them. Otherwise, the troublesome translations will be deleted.