Binance must be clear about the 0.9% Binance card transaction fee

Binance says they MAY apply a fee UP TO 0.9% to every transaction made by the Binance Visa Card. Both purchases and atm withdrawal.

If Binance was a bank this statement would be definely illegal because it's not clear at all.

1) First of all, what does it mean that it MAY apply this fee? What are the conditions? When I make a purchase, I need to know if the transaction will be free or if I'll have to pay a fee

2) what does it mean UP TO 0.9%? So it could be also 0.5%? Maybe 0.2%? What are the conditions? It depends on the weather? On how lucky I am? Is it a lottery?

I asked these questions several times to the chat support and they didn't know the answer. The faq are useless because they just say what I wrote here.

So, could Binance finally be clear about it?

By the way, I'm not using my card until binance will be clear about it, but some friends are using it and they say no fees are applied.