The Dad's Army opening sequence
A row between BBC bosses prompted a complete change to the opening titles of classic comedy Dad's Army, archive letters have revealed.
BBC One's controller at the time, Paul Fox, ordered shots of refugees and Nazi troops to be removed from the sequence as he found them offensive.
They were replaced with the now famous swastika-headed arrow sequence.
The BBC's archives are marking the much-loved series' 40th anniversary by releasing documents and pictures.
Michael Mills, the corporation's head of comedy at the time, expressed his "profound disquiet" and "shock" at changes to the title sequence.
A memo in the archive revealed that Mr Mills thought it "right and essential" that viewers were shown the Nazi threat faced by the Home Guard.
The series about the World War II Home Guard ran from 1968 to 1977
"I cannot help wondering whether we, in the comedy department, are controlled by different standards, i.e. clowns must stay clowns," he added.
They reveal that Fox initially "felt uneasy" about the series but admitted he had been wrong when it became a hit.
In a letter to Dad's Army's producer David Croft in 1970 he said: "You made an enormous success of it and like millions of others I am only sorry it has come to an end. Temporarily, I hope.
"Looking back to that first programme, I am glad to say you were right 100%.
"Thanks to your persistence - and despite that title change - the show became a great hit."
Croft's plan had been to illustrate the dangers faced by the elderly volunteers of World War II's Home Guard, the central characters in the show.
However, at the time Fox was uneasy about whether the series was "advancing comedy's output in other areas" and asked: "Is this really breakthrough territory?"
The much-loved show ran from 1968 to 1977 and its popularity has endured to this day.
Clive Dunn, Arthur Lowe and Ian Lavender starred in the series, co-created by Croft and Jimmy Perry.
As well as the internal BBC memos, the online archive also features a behind-the-scenes photo gallery and letters from the actors.
Jonathan Ross will be hosting a one-off special to commemorate the 40th anniversary on BBC One on Sunday, 3 August at 1900 BST (1800 GMT).