There are 46 million of the $50 banknotes in circulation since they were rolled out in October, and a spokeswoman on Tuesday confirmed the rest of the 480 million were locked away in storage vaults and would be dripped into circulation as needed. The trouble began when a member of the public – whose identity was withheld – alerted the RBA on December 20 to the error. "So is this meant to be a new security feature that is not mentioned on your webpage about the new $50 note – or did someone not check the spelling of 'responsibility' before sending these to print?" the eagle-eyed pedant inquired by email. "It is spelt wrong all the way thru [sic] microprint!"

Loading RBA governor Philip Lowe was "relatively relaxed". Not so for the folks at Note Printing Australia, who were "mortified" according to an email from deputy head of the RBA note issue department James Holloway on December 21 last year. He later said the printers, owned by RBA, "were devastated and had really been beating themselves up about it". "I said the fact they took such pride in the product was really the main thing, and reiterated the point about it being a relatively minor problem in the scheme of things," Mr Holloway said. RBA manager Luke Porter had also been managing broken spirits, comforting someone who was "in a bad way".

Illustration: Matt Golding Credit: "I told [redacted] the Bank is OK and don't stress too much – no one died. [Note Printing Australia] having a bit of a panic," Mr Porter said in the email. "I’m just happy my initial email to NPA had the correct spelling!!!!" Indeed, the RBA had provided the correct spelling to Note Printing Australia on December 21, 2016. By January 12, 2017, however, the typo had been accidentally added when Cowan's quote was "manually retyped" into the graphics software.

"The graphical software package used by [Note Printing Australia] has no copy-paste mechanism and no spelling or grammar check. The text was manually typed in and misspelt at this point," according to a report into the error from the printing agency, dated January 11 this year. The banknote went through an internal trial phase and was inspected by the printers, Banknote Projects and Banknote Quality. It then went into a review phase overseen by the designer and an independent designer. The Edith Cowan quote on the new $50 banknote. Credit:RBA So how did that go so wrong? Because the human brain speed reads, according to Note Printing Australia's report, marked "confidential". "The principle of isolated word recognition, which is the reading of words without the need to identify every letter, is used unconsciously by the human brain to speed up the process of reading words and gaining meaning from them. A well known example of this effect is the ease with which words can still be read when their central letters are jumbled, for example: Yuo cna porbalby raed tihs esaliy desptie teh msispeillgns."

It wasn't until May this year that the error was made public by a caller to a breakfast radio program. This was another cause for concern at the RBA. "Good luck," Mr Porter told the media team on May 9. "It appears somebody couldn't resist the urge to publicly announce the error with the NGB$50 micro text error – by ringing radio station Triple M in Melbourne this morning," said an email from Note Printing Australia to the RBA that day. The RBA has no plans to recall the banknotes as the typo does not affect their legal tender status. The error will be corrected in the next print run, expected to be October this year, according to the information release. The new notes, which feature Australian heroes Cowan and David Unaipon, were revealed to the public in February last year and circulated in October.