One of the guilty pleasures when returning from a flight overseas is shopping in the duty free shops at the airport. You'll find chocolates and wines and biscuits and booze and perfumes and liquor. There are usually other food stuffs, such as cheese and salamis. These shops are often staffed with people representing the merchandisers and they entice you to buy, emphasizing what a great deal you're getting because you don't have to pay the tariff.

But it isn't such a great deal if your purchase gets confiscated when you arrive in the states. That's what happened to a friend of mine when we returned from our trip to Europe earlier this month.

We had made it to Charles de Gaulle Airport in Paris with plenty of time to relax in the Air France lounge and then stroll leisurely through the duty free shops on our way to the gate. We both had leftover euros to spend but my carry-on bag was already almost too heavy to carry on, so I just browsed. Rick considered buying some Champagne -- after all, we had visited the Champagne region this trip and it would have been a good memento. We couldn't have brought a bottle of wine with us from Reims because we wouldn't have been able to get it through security (Champagne bottles under 3 ounces are hard to come by -- and totally useless). But the Duty Free shops are on the air side -- after you go through security. So anything you purchase there you're welcome to carry on to the plane.

But be careful: your purchases may not make it to your final destination with you. Not all of Rick's made it to Orlando.

That’s because we had a connecting flight in Cincinnati, and it has become custom for travelers coming into the U.S from overseas to go through passport control at the entry airport, collect any checked baggage, go through inspections, put your bags back on the conveyor belt to be rechecked to your final destination -- and then GO THROUGH A SECURITY CHECKPOINT AGAIN!

Yes, even though you passed through security on the other side of the ocean and never left the secure area of the immigration checkpoint, you have to remove your shoes, your belt, take your laptop out of its case, and present your quart-size baggie with its 3-ounces or less containers of liquids and gels. That 1.5 liter bottle of Absolut, the two-bottle gift pack of Bordeaux wines, the splash-on size of perfume, and the bottle of Champagne? They’re not going with you. In Rick’s case it was a four-ounce jar of mustard from Fauchon. (Most people -- including a lot of T.S.A. agents -- don’t know that even though passengers are restricted to liquids and gels no larger than three ounces a four-ounce container is allowed if it is medicinal in nature. I tried to convince the agent eying the expensive moutard that is was to be used for a mustard plaster, but she wasn’t buying it. She didn’t have to buy it -- she could just pick it out of the trash when we left.)

And don’t think that just because you’re not carrying liquid purchases that your duty free merchandise will make it on the next flight. Did you buy salami or cheese? Watch the ears on the T.S.A. German shepherd perk up as you wheel your luggage past. Dairy and meat products may be restricted.

So why do they sell these things in duty free, or why don’t the shopkeepers warn you? Well, as far as the liquids are concerned, you’re OK if you don’t have to make a connecting flight. And as far as the contraband consumables, there are different rules for different countries. And, frankly, some of the people selling the stuff aren’t all that concerned with whether you will get to enjoy them or not. Why should they throw up red flags that might prevent a sale?

This is very much a buyer beware situation. Make sure you know what you can and cannot take with you. If you find yourself with liquids that won’t pass inspection, you may be able to put those purchases into your checked bag before rechecking it through customs. But don’t be surprised if you open your luggage when you get home and it’s damp and effervescent.