How do you properly word an invitation for no gifts or flower arrangements?

(The family) cordially invites you to this whatever but/and requests that money be donated to (charity of your choice) in lue of gifts or flower arrangments. It normal to offer the guest someway to make a token gesture perhaps to charity, even if the gesture is a poem/wishes/memories on a card to hang on a tree or something non-monitary like that. People want to do something in return for the invitation otherwise they arn't being polite! It works both ways unfortunatly. Or just tag - "Close family flowers and gifts only." At the end of the invite and inform your close family what you mean!