I am wondering why you are contrasting carbon steel, stainless steel and Swedish stainless steel. Are you, perhaps, confusing semi-stainless steel with Swedish stainless steel. Swedish stainless steel is, as already stated, just stainless steel made in Sweden, obviously :biggrin:. And stainless steel just means that the steel contains a certain amount of chromium (some say 10,5% others say 13%, but thats not really important). Semi-stainless steel contains a fair amount of chromium, but not enough to classify it as stainless.
The reason a lot of knife makers and/or vendors state that their knives are made of Swedish stainless, is because it is generally considered to be of a much higher quality than German stainless, i.e. AEB-L (or 13C26) is much better steel than e.g. X50CrMoV15.