Highway vs All Terrain vs On/Off Road

[l008com]

It seems like a few years back, when I would look for SUV tires, the tires would be divided into a few categories:

Highway
All Terrain
On/Off Road
Off Road

But when I look now, it seems like All-Terrain and On/Off Road have been merged (at least on tirerack.com) into one group. Am I imagining things or has there been a shift in the way tires like this are categorized?

 

[HARDTRAILZ]

I only see street/highway and AT/MT categories for past several years. They have blended the styles so much there is hardly any big categories, but dozens of subsets.