One thing that I find mildly irritating and frequently confusing is the US habit of calling the # symbol, the pound symbol. The £ is the pound symbol.
I call # a hash symbol, or if you are of a musical bent maybe a sharp. Microsoft created a programming language called C# and it is pronounced C sharp, so maybe this is better name for programmers to standardize on. I have also seen the # called tictactoe and today I learnt it is also called an octothorpe.
