Another thing is regarding currently supported Serbo-Croatian (sh) language which is deprecated and unused I suppose. Is there a way to actually add Serbian Latin (as proposed in #1480) instead of that? Maybe I should move this discussion to the issue?

Could you please expand on that? Why is it deprecated? Also, we currently only support HTML5 language codes, which the language code mentioned in the issue is not. We might turn the direction around in the future (allow to provide any translations and map back into HTML language), but that's currently not a priority.

Could you please expand on that? Why is it deprecated?

It's not actually depracated, but it's an old version of current languages which were used mostly in former Yugoslavia. I'm fine with using it if there is no official code (as mentioned in this comment) for Serbian with Latin script.

It's not actually depracated, but it's an old version of current languages which were used mostly in former Yugoslavia. I'm fine with using it if there is no official code (as mentioned in #1480 (comment)) for Serbian with Latin script.

I can't really decide that, because I don't speak any kind of Serbian. Maybe the previous translators can comment, so we can reach a decision if that is a sensible path to take. Other than that it's not possible for me/us to judge, and please keep in mind that this might break expectations of users that currently use the code.