If you are audited, the IRS wants to see printed proof and, often times, original documents, for example receipts from expenses or contributions.
The tax code now is filled with regulations that not only adjust for inflation but phase in or phase out at different points, making tax planning impossible unless you have a clear road map of the rules and understand them.
They have been renewed year to year, but Congress is running late.
If you're even somewhat organized, you've probably been amassing a small pile of information related to taxes over the last few months.
The machine moves slowly, but the IRS has more funds and is increasing its enforcement activity.