“Made in the U.S.A.”

What It Means: A product does not have to be 100 percent American-made to bear this label, but its foreign content must be “negligible” (say, just the knobs on a big appliance), and the final assembly or processing of the product must take place Stateside.

“Best if used with”

What It Means: Often shampoo bottles suggest you use the matching conditioner—to keep the fragrances consistent or to avoid over- or undermoisturizing.
If You Decide to Mix It Up: Everyone’s hair is different, says Paula Begoun, author of Don’t Go Shopping for Hair Care Products Without Me (Beginning Press, $22, www.barnesandnoble.com): “What the manufacturer thinks will work together may not be what you need.” But random mixing can be a problem, too. For example, you might not want to pair a seaweed shampoo with a honeysuckle conditioner, or a moisturizing product with one designed for fine hair.

“Do not operate heavy machinery”

What It Means: This label often appears on medication that can make you drowsy or dizzy, and “heavy machinery” includes everything from a lawn mower to a car to a bicycle. “It’s anything that might cause you to hurt yourself or others if you push a wrong button or turn a knob,” says Nicole Petersen, an assistant professor at the St. Louis College of Pharmacy. No government regulations cover when or where these stickers must appear; each pharmacy determines independently when to put them on a given medication.
If You Do Operate Heavy Machinery: Drugs affect people in different ways, so Petersen suggests trying the medication at home and monitoring its effects. Keep in mind, though, that if you have a car accident while on the medication, you are more likely to be considered at fault.