37 C.F.R. 1.2 Business to be transacted in writing.

All business with the Patent and Trademark Office should be transacted in writing. The personal attendance of applicants or their attorneys or agents at the Patent and Trademark Office is unnecessary. The action of the Patent and Trademark Office will be based exclusively on the written record in the Office. No attention will be paid to any alleged oral promise, stipulation, or understanding in relation to which there is disagreement or doubt.

37 C.F.R. 1.4 Nature of correspondence and signature requirements.

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1. (b) Since each file must be complete in itself, a separate copy of every paper to be filed in a patent application, patent file, or other proceeding must be furnished for each file to which the paper pertains, even though the contents of the papers filed in two or more files may be identical. The filing of duplicate copies of correspondence in the file of an application, patent, or other proceeding should be avoided, except in situations in which the Office requires the filing of duplicate copies. The Office may dispose of duplicate copies of correspondence in the file of an application, patent, or other proceeding.

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A disclosure under 37 CFR 1.56 must be in writing as prescribed by 37 CFR 1.2, and a copy of any such disclosure must be filed in each application or other proceeding to which the disclosure pertains (37 CFR 1.4(b) ). "The presentation to the Office (whether by signing, filing, or submitting) of any paper by a party, whether a practitioner or non-practitioner, constitutes a certification under § 11.18(b)." 37 CFR 1.4(d)(4)(i). 37 CFR 11.18(b) includes paragraph (b)(2), which calls for a duty of reasonable inquiry to ensure that the paper is not being presented for any improper purpose, the legal contentions are warranted by law, the allegations and other factual contentions have evidentiary support, and the denials of factual contentions are warranted on the evidence.