Ever wonder what the “sell by” phrases on food labels actually mean?

You’re not alone, according to the Virginia Farm Bureau Federation. Many Americans have no idea of the actual meanings.

Now, the grocery industry has made a move to clear up the confusion, after 40 years of letting consumers guess, according to a release form the VFBF.

The Food Marketing Institute and the Grocery Manufacturers Association, the two largest trade groups for the grocery industry, have announced they will be adopting standardized, voluntary regulations to define product date labels.

Manufacturers currently use up to 10 label phrases, ranging from “Expires On” to “Better if Used By,” but now they will be encouraged to use two: “Use By” and “Best if Used By.”

“Use By” is a safety designation, meant to indicate when perishable foods are no longer good. “Best if Used By” is a quality describer—a guess by the manufacturer about when the product should be consumed for peak flavor.

“The voluntary standardization of product date labels will help clear up confusion for many consumers and hopefully address complaints for some,” said Tony Banks, a Virginia Farm Bureau Federation commodity marketing specialist.

“The label standardization will not eliminate all confusion; the process is voluntary for manufacturers, and there are some state and federal date label requirements for certain food products. But this may help consumers save on their grocery bills by reducing unnecessary waste,” Banks said.

Studies have shown that many consumers believe the current language signals whether a product is OK to consume. However, it is fine to eat a product well after its labeled expiration date. Those dates typically indicate one of two things: a message from the manufacturer to the grocery store about when the product will look best on shelves; or a subjective measure of when consumers will most likely enjoy the item.

Both the U.S. Department of Agriculture and a coalition of environmental groups have been asking the industry for clarity.

Americans throw away $218 billion worth of food annually, according to the Natural Resources Defense Council, which estimates that 398,000 tons, or $1.8 billion, could be saved through standardized date labels.

Participating manufacturers and retailers have until July 2018 to make the changes.