Wedding Gift Etiquette Question

<p>Not a parent, but a wedding etiquette question I thought parents would be able to offer help with.</p>

<p>I am attending the wedding of a very good high school friend next weekend-- the first wedding in our friend group. I have made a charitable donation in honor of their wedding to the band program of the school from which they recently graduated (where friend and her fiance first met), as their other registry is a "honeymoon registry" for a rather extravagant honeymoon where my gift would be just a drop in the bucket, and friend's fiance's wealthy parents will be picking up whatever is left over in the end (so why not give money to a group that actually needs it?). </p>

<p>I have a gift receipt that is about as lovely as an internet print-out of the payment section of the school's website, although it does note that it was made in their name and the dollar amount of the donation. I do want to make sure they know that I gave a gift in honor of the occasion, but I don't want to seem tacky. Should I include the gift receipt in a card, not include the receipt but mention the gift in the note I write in a card, or just tell them in person that the gift was made? Any advice appreciated (or if you have any other ideas to make this seem more "wedding gift-y", I'd appreciate those as well!)</p>

<p>I would give them a card and write a note that says the usual congratulatory stuff and tell them that in honor of this wonderful occasion, you made a donation to "X" in their names.</p>

<p>ETA: I would not state the amount of the donation on the card. If they want to know, they can find that out on their own.</p>