One rule decides whose language each word on a page is in

The portal shows its own words in your language and shows what an author wrote in the language they wrote it in. On a page that mixes the two — an English lesson read by someone whose portal is in German — that produced a single German verb sitting inside an English sentence. Each piece was behaving correctly on its own, and the page still read as broken.

There is now one rule for it, and it is about ownership rather than position: every word on a page belongs either to the platform, to a module, or to the author, and whoever owns it decides its language. The application's words follow you. The author's words stay exactly as written. A word that belongs to nobody — text typed straight into a view and never translated — is a bug, and it gets an owner rather than a special case.

The second half of the rule is restraint. Where the application has to place a control inside something an author wrote — the Run button on a code cell, for instance — it must use a symbol wherever a symbol says the same thing, and move the translated words into the tooltip, which is also what a screen reader announces. Nothing is lost, and no translated word lands in the middle of somebody else's sentence.

What changes today is the rule, not yet the controls. They follow it one at a time, and the code cell's Run button — the one that prompted this — is first in line; it loses its redundant label in a later release. The obvious alternative — making the buttons follow the course's language instead of yours — was considered and declined: it was tried once before, and it hands an English reader of a German course a page whose every control is in a language they cannot read.