Download links for the latest release in different locales?

The question surfaced at WPSE.

I tried some variations and the logic seemed to be

Portuguese Brazil:
Portuguese Portugal:

But I think I’m wrong in this assumption, as the Catalan subdomain also deploys the Canadian English version:

Last note: the main domain does not recognize a localized zip and answers with Release not found.

Is this documented somewhere? Or is each case treated separately?