Lost in the news about the Food and Drug Administration’s approval of genetically engineered salmon on Thursday was its long-awaited guidelines on labeling food with or without genetically altered plant ingredients.

While the F.D.A.’s stance on labeling — it is not mandating disclosure of genetically modified ingredients — has not changed despite intense pressure from both sides of the issue, it has added a bit of confusion to the mix for consumers and for those companies that are voluntarily including more information on their packaging.

For starters, the F.D.A. does not favor the most commonly used term, non-G.M.O., which hundreds of companies plaster on tens of thousands of products on grocery store shelves.

Short for “genetically modified organism,” G.M.O. conveys an overly broad and inaccurate meaning when applied to food products, the agency said.

“Most foods do not contain entire organisms,” the F.D.A. noted.

Rather, the agency would prefer labels that say something like “Not bioengineered” or “This oil is made from soybeans that were not genetically engineered.”

Whether any food companies will adopt this language, or begin using nongenetically engineered foods rather than non-G.M.O., is unknown at this point.

But major food companies have applauded the agency’s position to not require genetically engineered ingredients to be disclosed. The F.D.A. has determined that such products are not materially different from their nonengineered cousins.

Many food corporations have lobbied heavily against mandatory labeling, fearing that customers will be scared off by foods known to contain genetically engineered ingredients.