Over at Medium, I’ve just posted my latest piece of techy-etymological exploration, looking this time at the unlikely origins of Apple’s command key – ⌘ – in pre-medieval Scandinavia.

Known sometimes as the St John’s Arms, it’s a knot-like heraldic symbol dating back in Scandinavia at least 1,500 years, where it was used to ward off evil spirits and bad luck. A picture stone discovered in a burial site in Havor, Gotland, prominently features the emblem and dates from 400-600 AD. It has also been found carved on everything from houses and cutlery to a pair of 1,000-year-old Finnish skis, promising protection and safe travel.

It’s still found today on maps and signs in northern and eastern Europe, representing places of historical interest. More famously, though, it lurks on the keyboard of almost every Apple computer ever made—and in Unicode slot 2318 for everyone else, under the designation “place of interest sign.”

Simply click through here to read the rest of the piece.