Category:Intro/*

This makes those pages accessibles by the parent category for each language. Thye are reproducing the same categorization as pages in English. And thye follow the same logic that instructs since ever to categorise all translated pages (and their categories) by language. Even if they still contain only one page per language, this can change when there are more translated pages added). Those categories have existed since ever in English and their content in other languages also grows slowly.

They are not "pre-created" but created on demand, each time there's one page or subcategory referencing them.

And I absolutely don't see where "this makes lists of pages unnecessarily longer"; in fact that's the reverse, this makes them shorter by not mixing languages. There's no overpopulated categories, and otherwise there's no explicit "list" of pages to maintain, so I don't see what's your point. Everything reamins simple and you see a single simplified structure in English and the rest can come at anytime and ermain navigatable using the same scheme. I don't se why you'd like to remove these tyo make is site less navigatable for non-English languages, and have these translated page left unreferenced, unused, non seen by their intended audience. There's not a lot of these categories anyway for each language, they "close the gap".

Also you're not alone on the site. Those categoies have a long history and you may want to look at histories for English

Those categories don't have a long history. Most of them have one revision created by you. I wasn't asking about English, but about other languages.

Most of them aren't even translated, and translation wouldn't be very necessary either. It's just a category.

So I'm asking again: how are they useful? If by "parent category", you mean categories like Category:Localisation/ab or Category:Localisation/he, then that category is not useful either. There are no links to it from anywhere (except maybe the same category in other languages), and it doesn't include any useful pages.

Is there anyone who actually uses it for navigation or finding content? As far as I can see, those are just nearly-identical manually-created pages that include no content and serve no purpose. It makes sense to create categories when they serve a purpose for navigation, but most of these do nothing.

They are creating since ever according to the statement that is no the main category and all instructions, to not mix languages and categorize each langauge specifically. Yes they were essentialyl created by me, but because they were requested. And they have allowed the English categories to remain maintainable and all other *existing* translated pages to remain accessible and navigatable. Naturally, there are less translated pages then English pages, but their flow ghrows slowly over tyime and they can remain in sync with Engmish pages. The same thing is used in other multilingual wikis, so this is not new (and without it, the wiki was nearly unmaintainable and really difficult to navigate and maintain in *all* languages (including in English). And everyone can see what can be translated and what is missing. They are also crated each time there's a listed missing category. Their size is extremely small, they are used via search tools as well and allow more people discovering pages that *are* translated, and that *may* also need updates. Now translators can wok on translating pages that they want or are interested in. This wiki has always had the purpose of being multilingual and open to many languages (focusing it to English only would have been a serious defect, as a way to show that only English needs to be maintained, and thus that even this entire wiki would not be needed at all, Mediawiki itself would be for English speakers only; that's clearly not what the WMF wants and promotes since long, minorities have thei place and we must facilitate their integration and not exclude them). May be you don't care because you natively use two major languages and can use English as well without much problem. But your point of view here is clearly not as open as what the WMF promotes and wants. We are not here to speak only between technicians using English for everything, as if it was a requiremetn for all Wikimedia-supported projects. I respect minorities, but visibly you don't care about them and are not ready to give them a place for their voices.

You say that you created them because they were requested. Who requested them? Specifically, who requested the creation of Category:Intro/he? And who requested the creation of Category:Intro/dv?

You also say that their flow grows slowly over time. How many of the Category:Intro/* pages actually grew after you created them?

They are created when pages are listed in them. There's a tracking category for that. The verbal request with instructions is in the main category of the site since its origin in February 2009 (even before you joined this site) by Siebrand, with a small modification by Kaganer a short time after to make this even more explicit. So this is not new and its originating from the origin of this site!

Note: I wrote "on demand", not "on request" (there's no new request posted in some talk page, the demand comes from usage on translated pages). There's not been any change of rules.

During many years, managing categories was left administered, and they started proliferating and being unorganized or named inconsitantly. Slowly they were reintegrated. Now the iste only has 1 uncategorized category, the main cateogy in English. All pages are navigatable by categories. And when you say they are not referenced, you're wrong. All pages have at least one category. Their number does not explode, but they are all organized by language as instructed, Categories don't need to have lot of members, just to be consistant. They'll populate slowly as soon as some translated page needs one of them.

Can you please give a direct link to the page where Siebrand and Kaganer wrote it?

You wrote specifically: "Yes they were essentialyl created by me, but because they were requested" (sic). I'm trying to understand that request.

Oh, do you mean the text of Category:translatewiki.net itself?

I interpret it as an instruction to use the [[:Category:{{SITENAME}}]] and [[Category:{{SITENAME}}{{#translation:}}]] syntax when it's referenced, and I'm not even sure that this complex syntax is very useful for anything. There's nothing in those instructions that says to manually and intentionally create "Intro/*" categories for every language. That's neither a request nor a demand.

It's also quite confusing that Category:Intro/ab includes the page Translating:Intro/ab, but when you look at Translating:Intro/ab itself, it is categorized under Category:Intro. It's the same for Translating:Intro/he and Translating:Intro/cy.

Translating:Intro/fr points to Category:Intro/fr, which is actually useful because it includes multiple pages. But for most other languages, it just serves no purpose.

You looked badly. Translating:Intro/ab is in Category:Intro/ab, and so on for Translating/he or Translating/cy.

Translating:Intro/he is under Category:Intro right now. Translating:Intro/ab was under Category:Intro when I looked at it yesterday, and now it's indeed under Category:Intro/ab; I guess that something was updated in some caches. But OK, now it's under Category:Intro/ab, and what now? What is this one-page category for?

You still haven't answered the main questions: Who asked for these categories? Who thinks that they are useful except yourself? What are they good for except raising your edit count? You say that it's for "navigation", but navigation from where? Most of these pages have just one page, and some of them have zero pages, like Category:Intro/dv. There are no links to these categories from anywhere.

A lot of the Translating:Intro/* pages are barely actually translated; many of them, like Translating:Intro/ta, only have the title translated. Just because of that title and because one of the templates has [[Category:Intro{{#translation}}]], a red link to Category:Intro/ta is created. Because of how categories work now, to make it blue, the category has to be manually created. But is it actually useful to make it blue?