Were you permitted to accept tips in your previous role?

"In my current position, tips are often provided, but they are not expected. I would estimate that 20% of our guests do tip. Do you allow the acceptance of tips in this environment?"

If you were permitted to take tips, then it's okay to discuss this. However, you can add that, while you appreciate the small tokens of gratitude, you don't expect them. You're focused on providing the best service possible, regardless of whether or not the guest will tip you.

"We were permitted to take tips in my most recent position; however, I have worked in environments where tips are not provided. What is your policy surrounding tipping, here?"