Porridge

The script allowed the prisoners to swear without offending viewers by using the word "naff" in place of ruder words ("Naff off!", "Darn your own naffing socks", "Doing next to naff all"), thereby popularizing a word that had been recorded at least as early as 1966. Ronnie Barker did not claim to have invented it. In a television interview in 2003 it was explained to him on camera what the word meant, as he said he hadn't a clue. The word was actually a piece of slang for heterosexual men which was popular among homosexual men. It was an acronym for "Not Available For F******".

The closing credits listed the actors' names but not the corresponding names of the characters that they played.

Featured in Laughter in the House: The Story of British Sitcom (1999)