I loathe secret requirements in interviews and am up-front and explicit about what I'm looking for. Even with that guardrail though, lots of folks don't answer the questions I'm asking. So I guess a more general piece of advice would be: listen to the interviewer, listen to the question, and answer the question that was asked.

(This is the same advice I give people when I'm coaching them for FAA oral exams, incidentally. People really have a hard time listening to a question and answering the actual question.)