It's amazing that 33 years later, nearly all of these still apply. And nearly all are mistakes that are still being made.

Theses gems stuck out for me:

Eighty percent of all input forms ask questions they have no business asking.

A procedure should fit on a page.

And especially: Don’t make the user provide information that the system already knows.

This happens all the time, especially in e-commerce. And even moreso in paper form. For example, every time I go to a new doctor, I have to fill out 15 forms and 15 times I have to write down my name, address, SSN, insurance id, etc... Why can't the doctor's office, which already knows all of that, just print out 15 forms with all of that pre-populated?

Somewhat related: We build so many input forms demanding people provide data to the computer in a form that the computer can immediately read. The computer should work for the user, not the other way around.

Example: The FCC's Do Not Call web site has notes on its input fields that phone numbers have to be entered as numbers only. No dashes, parentheses, etc... How about the web site take whatever is input and strip out anything that's not a number? So basic, but I see this all the time.