It's worded somewhat poorly but you can see what they mean if you look at the terminals of the "a", "t", "j", and "f", for example, which combine a right angle

It's worded somewhat poorly but you can see what they mean if you look at the terminals of the "a", "t", "j", and "f", for example, which combine a right angle on one side and a curve on the other. They took the idea from the counters, but didn't apply them to counters. (The counters themselves however are a little more vertical than most fonts).