Guild Wars 2

What is Anet officially calling items with +Precision major +Power+Toughness minor?

It’s “of the knight”

Indeed, it’s “of the knight”. Also, it doesn’t exist on items and cannot be crafted: it’s only when an emerald is socketed into an item that the emerald will give precision (major), power and toughness (minor).

If you ever need to find out the names of stat combinations, check out this wiki entry.