Multilingual Docs: Linking Translation Siblings
Knowledge documents carry a locale and an explicit link to their translated counterparts — a specific mechanism, not a generic multi-language claim.
"Supports multiple languages" is a vague enough claim that it's worth being specific about what Knowledge actually does. Every document has a locale field — 'en' unless the author explicitly set something else — and, separately, a translationGroupId that links a document to its translated counterparts when one exists.
What translationGroupId actually does
This is the field that makes multilingual docs more than a collection of unrelated articles that happen to be in different languages. When a document is linked to translation siblings via a shared translationGroupId, the system has an explicit record that these documents are the same content in different languages — not just documents that happen to share a topic. By default, this field is null: a document isn't automatically assumed to be part of a translation group. Linking is something an author does deliberately when a translated counterpart exists.
What this enables in practice
With documents linked this way, a reader on one language version of an article can be shown a way to switch to a sibling in another language — the underlying data makes that language-switcher possible because the relationship between documents is explicit rather than inferred from titles or slugs matching by coincidence.
Setting up a translated document
When you create a translated version of an existing article, the two things to get right are the locale field on the new document (so it's correctly identified as, say, French rather than defaulting to English) and linking it into the same translationGroupId as the original. Skip the second step and you'll have two documents that are correctly labeled by language but with no system-level relationship between them — functionally two unrelated articles that happen to cover the same topic, rather than one piece of content available in two languages.
What this doesn't do
Linking translation siblings doesn't perform translation for you — it's a structural relationship between documents you (or your translators) have already written, not a machine-translation feature. If you're looking for automatic translation, that's a separate capability from what translationGroupId provides; this is specifically about making an existing set of translated documents behave as one coherent multilingual piece of content once they exist.