Anyway I said: It's rude to give nothing or a $20 note in a card. If you can't afford to give money, a decent amount, its etiquette to buy a gift instead. If you literally only have $20, go out and buy a gift with it, don't put it in a card like you don't care. What the hell is someone going to do with a $20 note? Buy a gift and wrap it up for goodness sakes.
When people show up with nothing at all, not even a card, well yes, that is beyond rude! Why would anyone show up at a wedding, eat, drink, be merry, but have not enough respect to even buy a small gift?
Ironically, everyone in this thread does go to a wedding with something, so you all believe in some type of etiquette.
Except shelle65 her presence is the gift........