Hi,

I've recently discovered that namespace names may have an ambiguity with interlanguage links: If a namespace name is the same as a language code, using it in wikitext poses all kinds of challenges.

Actual example: In the Tyap language (code kcg), the Wikipedia in which was created a few days ago, the Category namespace is called "Sa:", which is also the language code and, hence, the interlanguage link code for Sanskrit.

So, "Sa" is usable in wikitext, but has all kinds of little issues. For example, old-style non-Wikidata interlanguage links to Sanskrit from the Tyap Wikipedia are probably impossible. They are not very likely to be inserted into articles, but still, it's somewhat conceivable. I also noticed that it confuses Pywikibot in some ways. And I can imagine other subtle bugs that it will cause.

I've asked Tyap speakers whether it's possible to change the word for "Category" to something else. No—they want to use "Sa". It's legitimate not to want to change the word for a technical reason.

So what can be done?

The editors there told me that it's OK for them to use "[[Category:" in wikitext, but they would like to see "Sa:" in the title of category pages. I'm not sure that it's possible: as far as I know, the namespace name definition in MessagesKcg.php will be used for both things, and if Visual editor is used to add categories, it will add "[[Sa:". Bots or gadgets can be used to replace it to "Category", but is looks like an ugly hack.

Does anyone have better ideas for a robust, comprehensive solution?