Have a look at the food hygiene ratings. Just type in "Scores on the doors" and you might get a shock !
(Don't bother looking for us-- We were only done 10 days ago-- and got 5- the maximum !)
I was horrified to see what some of the bigger establishments had been given !
It seems to me that almost without exception, it is the establishments who have attained the highest rating, (5 stars), who actually post them on their doors. In the past I have looked at the ratings for all of the three towns, but it is only the poor performers that you tend remember, the 3's and 4's less so. How much better the scheme would be if it were mandatory to display their score, not only would this inform the public, but it would also be a big incentive to the particular business receiving a low to score take steps to improve it. However, I suppose like all systems, the methods applied to arrive at the ratings, will be rather rigid and some types of business may, try as they might, be unable to improve their score.