As the 1970s drew to a close, slogans on number plates were a novelty in Australia, though local attention had been drawn to the practice in America as far back as the early 1950s.

"Quite a number of the American states have novel and descriptive slogans on their number plates," a Goulburn Evening Post column said on August 20, 1951.

After Tasmania led the national charge with the 'Holiday Isle' slogan in 1976, some Australian states debuted with borrowed slogans from across the Pacific.

Queensland and Florida shared the 'Sunshine State' motto from 1977, while both Victoria and New Jersey were their countries' respective 'Garden State' in the same year.

Those administering the ACT had serious fears of missing out on this new phenomenon, noted a Canberra Times article on March 9, 1978, especially as NSW cars would soon be bearing down on the borders with 'The Premier State' emblazoned on the yellow and black plates.

"Attempts to introduce some similar identification in the ACT seem to be in a state of confusion," the story said.

"The Department of the Capital Territory is not averse to the idea, provided somebody can come up with some name acceptable. It is about to let a contract for the supply of more number plates and could incorporate an identifying slogan in these."

A matter-of-factly option, "Canberra - The Nation's Capital", was recommended later that year, with motor vehicles registrar Leon Webcke at pains to reassure motorists that the extra 26 characters "would not add to the costs of the plates".

But the idea did not win universal acclaim, considered by some to be an unwelcome, gaudy American import.

"If the ACT does decide to follow that juvenile practice of having a slogan on car number plates then I suggest that it should be 'Jawbone City'," Canberra Times letter writer Bert Castellari of Curtin helpfully offered on June 9, 1978.

"I personally would think it a better plan to conceal, as far as possible, rather than advertise, one's domicile when travelling interstate," BS Walker of Hawker said on June 2, 1978.

"I am quite sure that most other Australians already have enough of a 'set' on Canberra and its citizens, without us trying to outdo them in fancy number plate designs."

The advocates prevailed, and since 1979 Canberrans have advised interstate drivers that they are the "Heart of the Nation", urged them to "Feel the Power" of the city and helpfully corrected overseas visitors who believed Sydney was "The Nation's Capital".

If the interim results of the new number plate slogan competition at the time of publication are any indication, territory drivers will soon beckon fellow motorists towards "The Bush Capital".

1979 - Canberra - The Nation's Capital

1998 - Feel the Power of Canberra

1999 - Canberra - Heart of the Nation

2007 - Celebration of a Century 2013

2015 - Canberra - Age Friendly City