What does "give away cards" in the rules mean?
I have a question about the rules about the trade it says
> Important: You may not give away cards in any way, which includes trading matching resource cards (for example, trying to trade 3 ore for 1 ore is not allowed).
What does give away cards mean? Does that mean trading some amount of cards for a smaller amount of cards? Because typically I would not consider that to give away cards, and the rules don't specify what it means (it does give an example, but that is only for that specific case and is not a specification of what it means in general).
Like, when you trade with the supply or with a port, trading a larger amount of cards for a smaller amount of cards is what you do all the time, and then it's not called "giving cards away."
Edit: I misread the example given in the rules, and thought it was about trading one resource for another resource, but it was about trading one resource for the same resource. Hence my confusion.