Response: The purpose of a wishing well is to write the bride and groom small notes of congratulations or good wishes. If you are thinking about using it as a method to obtain money from your guests, that can be a problem and it may be offensive to some of your guests.
It is socially inappropriate to mention gifts in any way in a wedding invitation. Therefore, to mention a wishing well, if it is for money, would be a social faux paux. If you want guests to write notes of encouragement, then place small pieces of paper next to the well with a sign asking guests to use them to write a note and drop it in the well.
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