I haven't typically checked this box, even though I regularly being pre-packged snacks and candy back from Japan when I travel there. I guess I always considered it (incorrectly) to apply to things like meat, cheese, and fruits and veggies. I have a colleague who got caught trying to bring a wheel of cheese in from France. The cheese was confiscated, and that was about it. He knew it was a risk and decided to try anyways hoping he would be lucky.