Hide field, only visible through setup

Hi.

I'm trying to import a .csv file. I added all the necessary fields that I want to show when I am in accounts, contacts, etc. However, I need to import some "internal information" that I don't want to show with the other information.

Is there the option to have a hidden field so that I can use it for the import an then just acces to it via setup, layout?

Any other solution for this import problem?

Thanks a lot.