The new prison-based sitcom on the BBC - The Visit - will inevitably draw comparisons with the classic Porridge featuring Ronnie Barker. Indeed, it's rather difficult to imagine how the concept was pitched to TV bosses in the first place.
"We have this great idea for a new comedy. It's set in a prison."
"Really? That's a highly original idea. I'm surprised no one's suggested it before."
Perhaps the executives are too young to remember the 1970s? Or maybe they didn't have the guts to tell the writers to naff orf.