"Tu ești un avocat?"
Translation:Are you a lawyer?
According to my Romanian textbook, the custom is no article to be used with occupations unless the occupation is modified with an adjective. So I would have expected to see here: "Tu ești avocat?" (following the same convention in French) but "Tu ești un avocat bun!"
Or, is the rule more flexible in Romanian than described as above?
Good observation. We don't use the article in this case. The Romanian phrase should be reported.
Why should it be reported? The variant without “un” is more common, but both are correct.