If a clue is posed as a question but doesn't contain any foul play, is it okay to close with a question mark? It feels grammatically incorrect to omit one, but on the other hand, it feels unfair to mark it as unfair when it's not unfair... so to speak.
I think that's a contentious point: some will say yes, some say no. I'm not sure what Ximenes' view is.
Many setters use a "?" to indicate a definition-by-example (DBE), when some sort of indicator is obligatory by Ximmy standards.
Looking through my most recent offering on here (no.68), I see that in 10a/1a and 27a the ? is to indicate a DBE. But in 18a and 5d it's more about the surface.
@laccaria - thanks that's useful. It's cropped up a couple of times and I've opted to rewrite the clue each time due to uncertainty. Sounds like there's a reasonable argument for both so it's fair game either way.
I personally think it’s fine to use a question mark just for the surface reading.
I think a question mark is fine if there's any reason at all for it. It's not your fault if the solver misinterprets! 😀
I read Ximenes's book, and I do remember he advised against a self-congratulatory "?" or "!" - I do see quite a lot of those in the national press.