It's not difficult to get a double O number if you're prepared to kill people

Bond frowned. 'It's not difficult to get a double O number if you're prepared to kill people,' he said. 'That's all the meaning it has. It's nothing to be particularly proud of. I've got the corpses of a Japanese cipher expert in New York and a Norwegian double agent in Stockholm to thank for being a Double O. Probably quite decent people. They just got caught up in the gale of the world like that Yugoslav Tito bumped off. It's a confusing business but if it's one's profession, one does what one's told. How do you like the grated egg on your caviar?'

I. Fleming, Casino Royale (1953), 68