I looked at the form pretty close, and one thing I noticed was this:
It was about 20 or so questions, however many. They were enclosed in a kind of “blue box” compared to the white borders of the form.
Question 1 was basically how many people live here.
The odd thing was, question 1, AND QUESTION 1 ONLY was enclosed in a blue bow that was SLIGHTLY off color to all the rest of the questions in this other, much larger, blue box.
So it was almost like if you didn’t notice it, you would assume that all questions were required to be answered. But which ones actually were?
I filled in box 1 with 1, there is one inhabitant in my house.
If they knock on my door and ask my name I will probably ask them if I am under arrest, and if not, then they can pound salt.
I noticed that too. From the research I've done, I think it is a ruse - they know a lot of people know they can only count heads. But they also know that people don't have to respond to their head-counting. So they make a box around the head-counting question to make it seem it is the only thing you have to answer, when in fact, you don't have to answer anything. Then, if you answer that one question, they follow up and say, well you agreed to fill out the form by answering that question, so now answer the rest.
But no matter what (as I explained above), I don't see that you have to answer anything - now or later - no matter what you've volunteered so far.