Over the next few months, a select group of East London ATMs will prompt customers with utter disregard for the King's English. Instead, the machines will use a nearly indecipherable, rhyming cockney slang dialect.

ATMs run by a company called Bank Machine offer a language option allowing customers to enter their "Huckleberry Finn" instead of their PIN, and rather worryingly informs them that the machine is reading their "bladder of lard" at a prompt about examining their card.

The origins of Cockney rhyming slang are obscure. It is thought to have been used by market traders who needed a way of communicating without tipping off their customers.

It works by replacing a word with a short rhyming phrase. For example: "Money" becomes "bread and honey," which in turn is shortened to "bread." Similarly, "head" becomes "loaf of bread," and then just simply "loaf."