What information do personnel files usually contain?

Are they usually just things like position, gender, full name and date of birth etc? Or are there different kinds for different personnel like researchers and MTF operatives?

I assume they'd also contain extra files depending on whether or not they were involved in any incidents before or after they joined the Foundation?

I know there's technically no canon so I'm sure it's varied but I'd like to know generally which is the most popular approach, it would really help me out.