This might get superseded by T192701: Create an optimized language-fallback system for Maps internationalization based on investigations.

@CKoerner_WMF, as suggested, @geraki has gone to the community for consensus. If this looks good to you, we are prepared to implement.

@geraki, after we add the fallback, you'll want to be on the lookout for cases where a map of a Greek territory on a Greek wiki is suddenly showing English labels for things that should have Greek labels. This will probably indicate that there is a Greek local label but no Greek multilingual label (tagged with "el"). In such a case, you can declare the map lang="local" or go to OpenStreetMap and add the label in Greek with the "el" tag. The issue is described here.

https://github.com/kartotherian/babel/pull/17

@jmatazzoni Looks good to me. Thanks @geraki for helping with this.

In T193866#4195550, @Catrope wrote:

https://github.com/kartotherian/babel/pull/17

Now that this PR is merged, Babel needs to be tagged, a new package has to be published, and upstream repos have to use it for this change to ever make it into production.

In T193866#4198535, @SBisson wrote:

Now that this PR is merged, Babel needs to be tagged, a new package has to be published, and upstream repos have to use it for this change to ever make it into production.

So, will that happen now as part of this ticket, or do we need to create more tickets (and for us or other teams?). The word "ever" makes it sound hard.

I thought this process was simpler. I'm literally just about to write a post telling wikis how to get their fallback changed and, implicitly, encouraging smaller languages to do it. (I'm looking at you Catalan, which falls back only to Oc—which means Catalan maps of foreign parts are not good at all.) Does this raise a concern? Should I hold off, or, maybe, just raise the possibility but downplay it?

In T193866#4198569, @jmatazzoni wrote:

In T193866#4198535, @SBisson wrote:

Now that this PR is merged, Babel needs to be tagged, a new package has to be published, and upstream repos have to use it for this change to ever make it into production.

So, will that happen now as part of this ticket, or do we need to create more tickets (and for us or other teams?). The word "ever" makes it sound hard.

I thought this process was simpler. I'm literally just about to write a post telling wikis how to get their fallback changed and, implicitly, encouraging smaller languages to do it. (I'm looking at you Catalan, which falls back only to Oc—which means Catalan maps of foreign parts are not good at all.) Does this raise a concern? Should I hold off, or, maybe, just raise the possibility but downplay it?

It will be part of this ticket. All of that is easy and takes just 5 minutes.

The reason I wrote it here instead of doing it is to make sure @Catrope remains aware of it. Now that he's been pinged I will go ahead and do it.

Done. Will be deployed next week.