Nachi function codes

Do you want a list of function codes in a manual or are you trying to figure out what to use? This question is confusing as when you hit the FN key it pulls up the available ones. I also recall you can hit the help key to get an explanation of the code and an idea as to how it works. This is as far as I can go from memory but if you are more specific I can look at my training manual at the office.