Can new matter be introduced in a supplemental oath or declaration?
No, new matter cannot be introduced into a nonprovisional application through a supplemental oath or declaration. This is explicitly stated in MPEP 603:
37 CFR 1.67(d) contains the provision of former 37 CFR 1.67(b) that no new matter may be introduced into a nonprovisional application after its filing date even if an inventor’s oath or declaration is filed to correct deficiencies or inaccuracies present in the earlier-filed oath or declaration.
This rule is consistent with the general principle in patent law that new matter cannot be added to an application after its filing date. The purpose of a supplemental oath or declaration is to correct deficiencies or inaccuracies in the original filing, not to introduce new subject matter.
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