I'm in a firm right now for school, have to work their two weeks. The thing what annoys me the most, (look, two commas!) is the comma and point in the numbers. At school we have to use the BIN-norm, that means there are spaces between thousands and a comma before the decimals. Now at work, everything has to be WITH a point between thousands and a point between decimals.
And at school they all go like: you have to put the date like this: yyyy/mm/dd
At work they use the English norm, so that means: mm/dd/yyyy
It's really annoying, especially if you think about all the tests you get for you to learn this stuff, but in real life people don't use it.