“Don’t think about monsters,” 1972

Much of the NOI’s output was designed for the classroom. Campaigns like “Mind that rat!” and “Not everyone’s called Simon” still live on in the collective memory like nostalgia.

This poster – designed to reassure young heads destined for the pillow atop the wooden hill to Bedroomshire – appeared in every primary school the width and breadth of Britain. It was accompanied by a controversial Public Information Film, only passed by the BBFC after cuts which director Ken Russell said rendered it “disjointed and chthonic”.

The Welsh-language version (“Peidiwch â meddwl am anghenedlgarwch”) was withdrawn after a typogryphical mistake left the children of Wales baffled by the stern instruction, “Don’t think about a lack of patriotism”. It is no coincidence that the red dragon, for centuries the Welsh national monster, was removed from the Union flag shortly afterwards, in an unrelated incident.

“Whistling is killing music,” 1981

The success of the title song from Monty Python Live At Brian’s (1979) tempted millions to experiment with whistling, almost destroying the British music industry. Takings at concert venues and sales of LP records plummeted as ordinary people found they could make their own entertainment, a phenomenon Jonathan King described as “morally repugnant”.

Acting on instruction from the Lord Privy Minstrel, the NOI mounted this memorable campaign, which ran alongside a macabre television advertisement showing a young Dexter Fletcher whistling himself to death in a public toilet. The music industry was eventually revivified by the cassingle.

“Don’t delete that blank document,” 1995

The arrival of the electro-digital office coincided with a passing fad for environmentalism, leading to this well-meaning advertisement from the NOI.

The scientific adviser for the campaign was TV phlebotomist Roy Cheddar, who had become the public face of global warning after fronting the “shock-umentary” series Kettlesphere: Earth.

Cheddar claimed at the time that every one of these posters would save “enough trees to stretch a double decker elephant to the size of Wales and back”. By 2011, he had became a high-profile outspokesman for climate change denial, insisting his advocacy of environmental causes was merely youthful naivety. “I was green,” he told Kermit The Frog on Muppet Island Discs.

“Going upstairs? Get your jabs,” 1967

Little did NOI typing pool attendant Maureen Diddley know what she was letting her pussy in for when she agreed to his being photographed for this campaign. Honky, her lager-coloured four-week old Bodleian shorthair, soon became a national star, appearing on Ways Of Seeing, The Ascent Of Man and the ICI trousers advertisements.

Honky toys were the must-buy purchase at Christmas 1971, and his autobiography, Always Landing On The Same Feet (co-written with Fay Weldon) was the bestselling book of 1972, and won the Duff Cooper prize the same year, causing historian Robin Lane Fox to threaten to set himself on fire.

Honky later drifted into a life of homelessness and milkoholism, and died in a wet cardboard box in 1977.

“Watch That Girl,” 1967

The Singing Sixties were a high tide mark for female emancipation. The pill was introduced, hemlines headed north, and sex before marriage was legalised for women, as it had been for men in 1182. But this newfound freedom rattled some in Government, and, in an infamous speech he made in Doorford in 1967, Cabinet Secretary Sterling Bellend warned that

The once fairer sex has become a foul plague. There are now as many women as there are men in this sceptr’d isle, and the indigenous British male is in danger of being swamped by these giddy creatures. As I look ahead, I am filled with foreboding. I see the rivers of this green and pleasant land running red with their lipstick. And this must never be let happen, say I. We are men. We are resolute. We will not secede to Babylon.

Bellend lost his seat and three toes at a by-election shortly afterwards, and his career never recovered from what Joan Bakewell called his ‘rampant homomania’ in her 1968 single, Bubblecar Ding-a-ling.