37 C.F.R. § 1.68 provides
Declarations may be presented in lieu of an oath: if, and only if, the declarant is on the same document, warned that willful false statements and the like are punishable by fine or imprisonment, or both (18 U.S.C. 1001) and may jeopardize the validity of the application or any patent issuing thereon. The declarant must set forth in the body of the declaration that all statements made of the declarant’s own knowledge are true and that all statements made on information and belief are believed to be true.
If the required statement is omitted it can, if caught in time, be corrented, but the process set forth in MotivePower, Inc. v. Cutsforth, Inc., IPR2013-00274, Paper 15 (March 5, 2014) can be tedious.