This is expected, we have closed submissions for publican projects and are waiting for docs owners to merge the single PO files into the separate ones as mentioned on list.

I'm co-owner of this guide, and I already merged those files. TQSG is using ISO language codes, as every Publican doc. Transifex should recognize them as a valid languages, e.g. treat pl-PL, pl_PL and pl as the same language.

Is there a specification which states whether language codes should use dashes instead of underscores or the opposite? We need to choose one format and stick to it. I didn't find anything on ISO-639 on wikipedia.

This is not what this ticket is about. Testing project from the test Transifex instance is correctly binding xx-XX codes to their xx equivalents [1], and deployed Transifex is not, as you can see at the TQSG example.

[1] https://translate.stg.fedoraproject.org/projects/p/publican/c/virt-guide-localhost/

Using dashes is Publican guys decision which I don't particularly like, but it's out of the scope of this ticket.

Ahh, I see what you mean. I'm looking into why this is happening now.

It turns out we were missing some updated database entries with aliases for these language codes. Thanks to Ignacio for pointing out the command to generate these. Projects with this issue should be fixed on the next stat refresh.