Basic (Grade C)
Browsers in this category are known (listed below) and identified via a feature test suite and a blacklist in the startup module.
In conversations, a number of voices were referring to “navigable”, “readable”. These attributes might be fine on a Readers experience side, they don't mean enough on a contributors side. And more importantly, such attributes are nowhere in there currently.
In my opinion clarifying the language would enable product teams to make better choices about the roads needed to be taken and also help in future decisions on changes like T248061