When guests receive their invitations little cards tastefully announcing the register are enclosed. Once a monetary gift is received by the travel agency the guest is presented with a card telling the couple of their contribution to their honeymoon. The guest can then enclose it with the wedding card offering best wishes.
The agency keeps a record of the money received and those who have given, but not of individual amounts. This ensures that the couple is aware of who gave monetary gifts so that they can respond accordingly.
It should go without saying that the prospective bride and groom should be gracious about receiving the gifts and thanking the gift-givers.