Kellogg’s Frosted Flakes (Frosties in Europe) is a breakfast cereal first introduced by the Kellogg Company. It consists of corn flakes “frosted” or coated with sugar. The “Frosted Flakes” name is used by Kellogg’s in United States and Canada. The cereal was first introduced in 1951 as Sugar Frosted Flakes. The word “sugar” was dropped from the product in the 1980s during a time when many cereals dropped “sugar” from their titles.
“Frosted Flakes”, by itself, is purely a description of the product. As a result, that term cannot be trademarked and can be used by any company making a similar product; thus, on boxes, the words “of corn” are added below the Frosted Flakes logo. By contrast, “Kellogg’s Frosted Flakes” and “Frosties” are registered trademarks in their respective markets.
Info gleaned from Wikipedia