There are no strict rules regarding stapling of pages of Form N-400, Application for Naturalization.
However, there are general tips for preparing your packet, that apply to all and every USCIS form:
-Do not use binders or folders that cannot be easily disassembled.
-Do not use heavy-duty staples, use fasteners or heavy clips instead.
-Use fasteners to hold together a thick bulky application. Two-hole punching the top of the material for easy placement in the file is appreciated.
-Sticky tabs assist in locating items listed as attachments. For easy filing, place the tabs on the bottom of the page, not the side.
-Do not submit oversized documentation unless it is necessary.
-Do not submit originals unless specifically required.
If you need extra space to complete any item in the application, use and attach a separate sheet of paper.
If you are sending few applications in a single envelope, for example, when sending your family’s N-400 applications in the same envelope, you should clearly separate the cases by rubber bands or fasteners. Meanwhile, you may use separate envelopes for each family member as well.