I've recently transferred some funds internationally. To do this I needed a special account code so that the bank I'm sending money to know which of the accounts they hold should receive it. This number is a conventional looking account number, prefixed with a country code, and a checksum value. There is also a website that checks them - http://www.apacs.org.uk/payments_industry/ibans_5.html
BTW - Sorry for the Rodney Dangerfield knock-off quote. He's awful.