The film and the earlier musical comedies are based on a popular cartoon character Old Bill, an Cockney-born British infantryman, drawn by Bruce Bairnsfather.
The second filmed version of the hit musical comedy that was originally performed on the London stage, while World War I was still raging, in 1917. It ran for 811 performances.
By the shoulder patches on their uniforms, Old Bill is part of the British Army's 42nd (East Lancashire) Division - although the patches have been sewn on upside down (possibly deliberately). And by the two stripes on Old Bill's lower left sleeve, he had been wounded twice during the war.
The title, spoken in a Cockney accent, refers to: "The Better Hole" - as in foxhole in World War I.