Actually, looking at the original post, we seem to be talking about situations in which titles are used. I think it's true to say that in the UK we would be fairly unlikely to describe Gordon Ramsay as "Chef Ramsay" though we might call him "Mr Ramsay". Chief (of police) O'Neill would be another example.

It seems to be that it's about whether a job description can be used as a title or not. Of course, we call medical people "Doctor Soandso" or just "Nurse" but other than that it's not common usage in the UK to use job titles (Engineer This or Fireman That). I think Crow Sister might have been commenting that this appears (it does to me, anyhow) to be more common in the USA.

:-)