In Britain it's 999. In America it's 911. On a submarine it's S.O.S. In the air it's Mayday, mayday. And in space it's 'Houston we have a problem'.
Amid all this confusion, it's good to know the world will soon be able to rely on one, simple, easily recognisable, international call for help: AAAGH.
AAAGH has been chosen because it's quick to text and fast to type. Easy to dial by phone (22244). Easily pronouncable in 65 different languages. And in strict laboratory tests, volunteers have used it instinctively.
So as not to cause undue alarm on a 'plane, the phonetic version, Alpha Alpha Alpha Golf Hotel is recommended. But in a hurry, it can be spoken as written.