The most obvious and prevalent difference between American English and the British-Australian version is the tendency for Americans to just use "o" when others would use "ou".
It is this slight difference in words such as "favour" and "colour" that is causing a ruckus amongst the millions of people that are playing the viral word game Wordle which uses American English, despite its UK origins.
But there is one Australian word that could work just fine — the Australian Labor Party ditched the "u" in "labour" more than a century ago.
So why the break from the perceived norm?
The origins of the Australian Labor Party dates to the 1890s, before federation, with a presence in colonial parliaments in Queensland, NSW, Victoria, and South Australia.
"In the labour movements, the trade unions that formed the Labor parties in the 1880s, and also the broader socialist movement at the time, there was a lot of reading of American texts in particular," political historian Frank Bongiorno said.
Mr Bongiorno said examples include a "utopian socialist novel by Edward Bellamy called Looking Backward, which was a kind of projecting forward to the year 2000 and what a socialist future would be like".
And Henry George, an "American reformer and advocate of tax reform, particularly land taxation, [was] again very influential in radical labour movement circles".
The ABC's language research specialist, Tiger Webb said, like many words in the English language, "labor" was derived from both Latin and French, with the former using the "o" spelling and the latter using "ou".
Both spellings today, which are thought of as American, were used globally into the 19th century. It wasn't until 1828 that Noah Webster published his comprehensive dictionary of American English, which championed spellings such as "color" and "center".
It was not until the 20th century where the shift in Australian and British English was complete.
So in 21st century Australia the distinction is jarring.
Elsewhere, the "labour movement" and labour parties in places like New Zealand and the United Kingdom all use the "ou" version.
The Australian Labor Party, its state and national entities, stand alone in the shorter spelling.
Webb believes Australian Labor officially settled on the spelling in 1912.
"From the beginnings of Labor's federal caucus in 1901 they did go either way," he said.
"In 1902 it was 'or'. In '05 it was 'our'. In '08 its was 'our'. In 1912 it was 'or'. And it has stuck since then.
There is another theory that Webb said was repeated frequently that he was keen to debunk, "that it was all to do with King O'Malley who was a very influential early Labor Party chap in parliament in Australia and he was American by birth".
"So the thinking is he championed the spelling and he was himself personally enamoured of spelling reform," Webb said.
"But the 'or' spelling for Labor predates him."
Mr Bongiorno agrees.
He said he was not sure how conscious the ultimate switch was at the time, but thinks it came down to "usefulness" and "branding".
It is that take that the president of Australian Labor, Wayne Swan, agrees with.
"Throughout history there's been that historical association between Labor parties and the wider labour movement, which also includes trade unions," he said.
As to whether or not the spelling could ever change back, Mr Bongiorno said "there would have to be some kind of crisis or critical juncture in order to move away from that".
Mr Swan said the spelling was "fine" and here to stay.
"The Labor Party is a political movement concerned with policy across the board.
"I think the distinction works and the spelling goes with it."
