Hygiene factors

In the UK, restaurants are inspected for hygiene and given a sticker which, according the Food Standards Agency, they are 'encouraged to display on their door'.

You never, ever, see one of these displayed.

But you see quite a lot of these.

There doesn't seem much point in the scheme if the outcomes aren't public - or do we conclude that no sticker means they are too embarrassed to tell us their rating?