Guys,
I think you need to be careful here.
It is my understanding that the categories - say, Winter - have no official designations. HOWEVER, the fact is that there ARE standards and regulations and for example, some places say that is required for tires to display the Alpine symbol (aka 3PMSF) to be used during certain parts of the year that we normally call winter - hence the name "Winter Tires".
I know, I know. That sounds like a lawyer talking - and that is exactly what it is! Laws and regulations are written in such a way that it takes talking like a lawyer to make sense of it.
I think what we have going on here is what people call certain types of tires. For example, a "Winter Tire" nowadays has the Alpine symbol (aka 3PMSF), but the term "Winter Tire" isn't called out in the regulations. It's just that we call those types of tires "Winter Tires" as a shortcut in the language.
What did we do BEFORE the invention of the Alpine symbol (aka 3PMSF)? This was the problem confronting regulators in Canada in the mid 1990's, so they asked the CRMA (Canadian Rubber Manufacturers, now known as TRAC - Tire and Rubber Association of Canada.) who in conjunction with the US based RMA (Rubber Manufacturers Association, now known as the USTMA - US Tire Manufacturers Association) developed the test and the symbol. This allowed the regulators to specify what tires would be acceptable.
So they didn't have regulations and the term "Winter Tire" had virtually no official meaning - just a marketing one.
Right now, there are no regulations specifying what "All Season", "Summer", "All Terrain", "All Weather", etc. actually mean. That also means that people use these words differently in different parts of the world.
In the US, by convention we call summer tires those that don't have the M+S symbol. There is a regulation about what tires can display the M+S symbol and by convention, we call those All Season.
What I am trying to say is be careful when you apply a name to types of tires because we don't all use the terms the same way.