Indexing multi-regional sites?

Question

Google

A multi-regional site is being made (that is, a choice of languages ​​is supported) with custom content generation. The question is how to properly organize the indexing of this site, especially in light of the fact that Google does not support the lang attribute. Those. Let's say a user wrote an article with ID 25 in Russian and it became available at the following links:
ru.example.com/article/25/
en.example.com/article/25/
de.example.com/article/25/
etc.
On each of these pages, the interface is in the corresponding languages, but the article itself is everywhere only in Russian. How will search engines handle this situation, and how can they make this job easier for them?

Answer 1

They wrote especially for you:
webmaster.ya.ru/15326
support.google.com/webmasters/answer/189077?hl=ru

Answer 2

If we talk about Google, then you can just score. After six months, he has not made any fines for such content, and he himself is excellent at sorting out such content. In fact, Google supports the lang attribute, but it detects languages ​​automatically and on its own. The value of the lang attribute is rumored to affect only the speed of indexing (which I do not believe).

Answer 3

better site.com/ru/article/25/
> On each of these pages, the interface is in the appropriate languages, but the article itself is everywhere only in Russian. How will search engines handle this situation, and how can they make this job easier for them?
Like duplicates. Facilitate - no way (but why?).

Answer 4

In the case of Janga, a special middleware will be used in both cases, so there is no difference in this regard. Yes, and adding a language is not so common, so there are no problems with the NS record either. As for the weight, I'll try to look into this issue.

By the way, why publish an article in another language? Wouldn't it surprise you if you found an article in Chinese at site.com/en/article/25?

more precisely, the search engine is on the drum, but users, seeing articles in an incomprehensible language, may behave differently, and based on their behavior, the search engine will consider the page less valuable

Of course, I would like confirmation about “it will be on the drum”, because the link that I provided in the question directly says: “You can help to make language recognition easier if you stick to only one language per page and avoid side-by-side translations.” . Do not forget that search engines take into account the language of the page when issuing results.
As for surprise, I personally would be more surprised if I had to go to the Chinese version of the site to view the article in Chinese. For greater clarity, you can take some social network in which, even when viewing content in another language, the interface remains in your native language.

But this I never understood

In some situations, it is necessary to distinguish between regional features. For example, even the same British and American English differ , to say nothing of more exotic cases.

Answer 5

set the article on the subdomain where it was written rel="canonical"