Hand and Brain

So first, I know, that this question has already been asked... kind of.
I want to play Hand&Brain with my friend - we would obviously only do it in casual games.
Is that against the "Do not cheat or receive assistance in games (from a chess computer, book, database or another person)" rule (taken from lichess.org/terms-of-service), or is it "legal"?

Thank you in advance!

Think it's "legal". Not sure, but 80 per cent!

We allow it in casual games.

@anonmod , Hand and Brain is considered as cheating! Does Lichess officially allow "any form of cheating in causal games"?

No. But we do allow Hand and Brain.

Editted

Only casual? kinda unfair but ok

Sorry on mobile currently so not visible don't mind lol

#3 I honestly did not know that.

what is hand and brain?