I had a look through quite a few of these, and they all seem to be fixed now. Also quite a few of the things mentioned are opinions. There were also a few instances where I noticed w3fools was wrong.
Anyway, I see why w3fools decided to remove the list of now-fixed "errors". Thanks for wasting 15 minutes of my time - I'll bill you later :)
Damn those "hipsters" and their preference for valuing getting a real useful answer over an easy to read wrong answer!