Porridge originated as one of seven pilots in the Ronnie Barker showcase series Seven Of One. Another one of the programmes, I'll Fly You For A Quid, was also written by Clement and La Frenais. The BBC liked both programmes so much that they commissioned a series - leaving it up to the two writers and Barker to decide which of the two they would actually produce.
Long before Porridge came to life, Ronnie Barker had had an ambition to make a prison-set comedy. He would later describe the series he envisioned as being more like 'Bilko' (American sitcom The Phil Silvers Show).
In the pilot episode, Prisoner And Escort, Mr. Barrowclough's name is spelled Barraclough.