Also, just because clues can be solved easily doesn’t make them fair, as critics of Araucaria (usually ‘Ximeneans’) will tell you.

I’ve not read Ximenes or Afrit, but the justification is in Mr Manley’s own book (Chapter 19: Basic Principles of Crossword Grammar). He agrees that “an adverbial phrase cannot be used to define a noun” but he also goes on to say:

“By convention, it is permissible for a noun to be defined by a verb, as in this clue:
One party after another is really dead (4)
(‘do’ plus ‘do’ equals DODO). Here the definition is understood to be ‘[It] is really dead’ with the ‘it’ understood.”

Now, I don’t especially like this example. And I’m also slightly uneasy about justifying a clue from a reference source by the same author. But he’s right. The important part of the quote being: “By convention”. It’s convention that dictates that this kind of clue is acceptable and so, as you very rightly say, we have to like it or lump it. Accordingly, “[it] covers head” is a valid definition of wimple.

My comment about bad editing was tongue-in-cheek – I find it so hard to believe that Pasquale could bring himself to write a non-Ximenean clue that I had to imagine the source of blame lay elsewhere. But this only applies if you accept that the clue is non-Ximenean, which I don’t.

Back to KERBSTONE, “by the way” cannot possibly be a valid definition for a strict Ximenean. But for the rest of us, the clue may be considered “fair” in so far as one is able to find the correct solution without difficulty.

Doing crosswords is somewhat superficial. Doesn’t save any lives or put food in mouths etc etc.

Somebody should have thrown that back at me!

Maybe, “as found by the wayside”?