I've worked in restaurants in two states, MI and OK. Neither state required or expected a "letter" grade to be posted at the front entrances.
I worked at a steak house for a little while. My very first week there, we had a Health Department inspection. We had two hours warning before the inspector showed up. I was like, "what the???" I still had my Food Handler permit from Tulsa County, OK, when that happened. I was shocked that Jackson Co, MI, didn't require Food Handler permits of all food service workers.
That inspector arrived, and immediately went into a closed-door conference with the owners in the office. After about 20 minutes, the inspector came out, looked around for a few minutes, then realized that I was a new employee. He immediately started grilling me on temperatures, handwashing practices, etc. He couldn't stump me. He asked me why I was so "up" on all of this, then I showed him my Food Handler permit. The inspector left shortly afterwards.
Fast forward 4 months. In that time, the restaurant was sold to a new owner. The Health Inspector made an "unannounced" visit, and slammed the new owner. Almost to the point of shutting the place down.
Come to find out, the original owners would often "buy" a passing inspection from said inspector, which is why they had the "advance warning". When the new owner took over, the Health Inspector didn't get his regular bribe, and slammed them.
I ended up leaving that place shortly thereafter. It was going downhill, and I could see the writing on the walls.
Peace, Love, and Vegetable Rights!
Eat Meat and Save the Plants!