Is this not true for good documentation?
Without losing sight on the fact that the article does have value, I feel a rant coming on. Why state "there are six" when the items below the statement are numbered? Why not write "Here are principles for determining the order of questions in a form"instead? Is clarity gained by repeating the number? Is clarity lost by excluding it? To me, I'd say clarity is NOT lost by excluding it.
Read the whole article here: http://www.uxmatters.com/mt/archives/2017/05/designing-ux-forms.php