 There were working titles, such as "USA" for "Waldorf Salad", "Death" for "The Kipper and the Corpse" and "Rat" for "Basil the Rat", which have been printed in some programme guides.In addition, some of the early BBC audio releases of episodes on vinyl and cassette included other variations, such as "Mrs. Richards" and "The Rat" for "Communication Problems" and "Basil the Rat" respectively.It has long been rumoured that a 13th episode of the series was written and filmed, but never progressed further than a rough cut.