You can't trademark a noun. You can trademark a product. Frosted Flakes are an adjective, Flakes are a style of cereal and Frosted is another style. They can be bran Flakes, oat Flakes, cinnamon Flakes. The game is wide open. Trademarking frosted Flakes would be like some company trademarking ravioli, spaghetti, rigatoni, angel hair. These aren't brands they are styles of pastas.
But "Pops" is a trademark of Kelloggs. There will never be Post Chocolate Pops cereal. Cookie Crisp is trademarked there won't be Kelloggs Sugar Cookie Crisp. Froot Loops is trademarked. They arent claiming to be fruit so any other cereal can be fruit or fruity, however they are 'loops' I don't know if any other cereal can claim to be loops. They can be hoops and rings, O's , wheels, spins, and circles but I don't know about loops.
Even band-aids are a brand not a product adhesive strips are what bandaids are called but everyone associates adhesive strips with probably the most known brand bandaids even if they buy the knockoffs.
Rice Krispies is trademarked, but there is still crisp rice and crispy rice.
Came here just to say that.