The curious language of bureaucracy

I have misplaced my social security card, so I went looking for how to get a replacement. I arrived at the Social Security Administration website; found the appropriate PDF and the location of the closest office where I can turn in the form.

After printing out the form, I begin to fill it out. It asks for the typical stuff, but then comes to a section which asks for the names and social security numbers of both parents. Well, that seems a bit much. Under this there’s a note to check on page 2 for the instructions on item 8.B. in the form which read:

8.B. You must show the mother’s Social Security number only when the application is for an original Social Security card for a person under age 18.

Well, okay, then. I don’t have to worry about it. But, then I read the rest of the instructions for item 8.B. which continue:

However, this item may be left blank if the mother was never assigned a Social Security number, or if you do not know the mother’s Social Security number and are unable to obtain it. We will still be able to assign a number to the person under age 18.

Huh. They kind of went off message there at the end. “Must” must not mean what I think it means.