An American tried to tell me off for using the word "Rubber" during my NATO tour - I was looking for one because some swine had stolen the one from my office. I told him that the word rubber was official English as prescribed by NATO and would not change it. I also pointed out that a rubber was a device that slipped on the top of your pencil, to be used in the event of any mistakes. The best ones were larger and could be used for a long period of time without leaving dirty streaks - I had used mine for many years. They also have the benefit of preventing chewing although you could buy some of them that smelled of strawberries when you rubbed them hard. By the end of the tour, I had convinced the staff from other nations to also use the correct form of the word!
