Because it's not considered 'proper' to include registry information on a wedding invitation, you'll have to ask the bride or groom's family where the couple is registered. In most cases, it's best to stick with gifts from the registry list. Otherwise, you run the risk of giving a duplicate item, or something they'll have to return. Exchanging gifts can be a very time-consuming chore, so show your consideration by giving a present the couple has already selected. If the couple isn't registered anywhere, their family may have some ideas. You might consider giving them a gift certificate for a service, like house cleaning, landscaping, lawn care, or renovation. Or, you might simply give money. Though some people may frown on a monetary gift, it's doubtful that the bride and groom will. In many cultures, money is a customary gift. However, traditions vary by region, so if in doubt, ask around, as to what's considered acceptable in your part of the country. Whatever gift you choose, send it to the couple before the wedding. Having to haul gifts home from the reception is inconvenient; and the presents could be lost or stolen.
