Can you find what you saw and where you saw it?
In the opening post, there's this about exchanges:
22. Advertising (this includes mining pools, gambling services, exchanges, shops, etc.) in others' threads is no longer allowed, including, but not limited to, in altcoin announcement threads.
Nothing about signatures in there.
And to add to Xal0lex reply, here is the rule from the opening post about referral links:
4. No referral code (ref link) spam.
Spamming would be positing irrelvant messages with your referral link, including messages saying "check my signature"
So it looks like you are safe to put a referral link in your signature.
thank for your advice kaicrypzen
To be honest, I don’t remember exactly where I saw it now, it was several years ago in a local (Russian) chat, it seems
thanks for answer Xal0lex. But i worry what my link this is exchanche Binance. (I have long seen somewhere on the forum that links to exchangers are prohibited)
This is the first I've heard of it. What is the difference between a Binance referral link and referral links to other services? Or is it forbidden to mention Binance on the forum?

No, of course, binance is not forbidden to mention on the forum. and this platform is mentioned quite often. )