Why a per-language baseline matters
The provenance-mark test itself is language-independent, since it counts word pairs against a keyed partition, and that arithmetic does not care what language the words are in.
The style measurement is a different matter. It compares your document to a reference corpus, so the reference has to be in the same language or the comparison is meaningless. Every deviation would simply be measuring the language difference.
WatermarkRemoverPro measured its French baseline from contemporary French prose, and every document in that corpus was verified to be French by the engine's own language identifier before it was included.
If the language cannot be determined
When the engine cannot confidently identify a document’s language it stops and asks, rather than picking the closest match. Analysing against the wrong baseline produces a real-looking number that means nothing at all, and a real-looking meaningless number is worse than no number.
You can also set the language explicitly before running the check.
Wherever this page describes a result: a detected mark is not proof of authorship, and an absent mark is not proof of human authorship. WatermarkRemoverPro's on-device rewrite can reduce detectable evidence but cannot guarantee defeating a vendor's undisclosed watermark, on any tier.