How Spam Filters Dictated Canadian Magazine's Fate

After 90 years, one of Canada's oldest magazines, The Beaver, is changing its name.

Its publishers say it was only natural that a Canadian history journal should have been named in honour of the industrious dam-building creature which is the country's national emblem.

But in recent times the magazine's attempts to reach a new online audience kept falling foul of spam filters — particularly in schools — because beaver is also a slang term for female genitalia.

Deborah Morrison, publisher of the Winnipeg-based journal, told the BBC News website: "Back in 1920, The Beaver was a perfectly appropriate name.

"And while its other meaning is nothing new, its ambiguity began to pose a whole new challenge with the advance of the internet. The name became an impediment to our growth."

The blocking of harmless websites or e-mails by trigger-happy filters is nothing new.

In 1996, residents in the British town of Scunthorpe were initially banned from registering with internet service provider AOL because the town's name contained an obscenity.

This became known as the Scunthorpe problem.

Such ham-fisted cyber prudery might have been forgivable in the internet's infancy. But why are some filters still apparently unable to distinguish between clean and dirty content?

The problem, technology experts say, is that with a worldwide web awash with filth, broad blocking rules often result in a false positive, meaning innocent content is binned just to be on the safe side.

In a farcical sequel to the Scunthorpe problem, some filters have been known to act like rogue spell checkers, replacing "rude" words with what they deem to be more acceptable variants.

"Butt" replaces "ass", "breast" is substituted for "tit", and so on, even within longer words containing the banned letter combinations.

This is known as the "clbuttic mistake", because classic is edited as clbuttic, passport becomes pbuttport, and so on.