Based on his experience working at Piccadilly department store Simpson, Jeremy Lloyd's original pilot script about a gentlemen's outfitters was entitled Fun In Store.
Although generally established as 'Humphries', the spelling of Mr. Humphries's (John Inman) surname is given as 'Humphreys' in the final episode of Series 1, Diamonds Are A Man's Best Friend, with a character named as 'Mr. Humphreys Friend'.
Mr. Lucas's Christian name is given in early series as James, but he is later and more consistently referred to as Dick (Richard) Lucas.
In Series 4 Episode 5, Fifty Years On, Mrs. Slocombe celebrates her 46th birthday.
Although there are references to other floors, the Ladies' Intimate Apparel and Men's Ready To Wear departments are most consistently referred to as being on Grace Bros. fourth floor.
The branch of Grace Bros. depicted in the show is said to be "on the High Street", with other references only pinpointing its location as somewhere in north London.