On 2005-10-10, Steven P. McNicoll wrote:
In what part of America is 'numbers' just an American figure of speech?i

The United States Of.

US
plane registrations are colloquially known as 'N numbers' because they are
predominantly numbers. Many are exclusively numbers.

But not all. People still call their plane registration 'their N-number'
when it's something like N23AD even though the last two characters are
letters.

--
Dylan Smith, Port St Mary, Isle of Man
Flying: http://www.dylansmith.net
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de
Frontier Elite Universe: http://www.alioth.net