But it's not working. Not working means: Even though I said
<!-- language: lang-none -->
before the start of the block, a couple of characters are still highlighted, probably because of the Python tag to the question.
Also thought this (rerendering after in-page edit) might be an issue, so that only I see the wrong highlighting. But that's marked as fixed.
Is it my fault or a bug or none but expected behaviour? If the latter, why would we want this?