When someone says "salts" when discussing plant nutrients they are talking about the ionic form of that nutrient, and the ionic, or salt form, is the only one that plants can use. Those ionic salts are identical even under a microscope, there is no way to distinguish one from the other, so it matters little what's in the nutrients. NOW, when you start talking about all the various additives, "bloom boosters", "bud hardeners" etc, then you open a can of worms because the often use PGRs, plant growth regulators, and other hormones, some of which are actually banned....... but they get away with it.