Currently the constraint parameter for language code of the required labels (P424) is string and doesn't care if the language code is a valid one or not.
This is better to be changed.
See T195178: New constraint type to ensure that Items have a Label in a specific language for more context.
Hi @Addshore, would this be something for tech polishing? I could also bring it to camp as is?
To me this seems more like a product than a tech task. I don’t think there’s a need to do this from the technical side – as far as I can tell, if the constraint is configured with an invalid language code, the checker won’t crash, it’ll just report a violation everywhere.