37 CFR 1.948 - Limitations on submission of prior art by third party requester following the order for inter partes reexamination.
(a) After the inter partes reexamination order, the third party requester may only cite additional prior art as defined under § 1.501 if it is filed as part of a comments submission under § 1.947 or § 1.951(b) and is limited to prior art:
(1) which is necessary to rebut a finding of fact by the examiner;
(2) which is necessary to rebut a response of the patent owner; or
(3) which for the first time became known or available to the third party requester after the filing of the request for inter partes reexamination proceeding. Prior art submitted under paragraph (a)(3) of this section must be accompanied by a statement as to when the prior art first became known or available to the third party requester and must include a discussion of the pertinency of each reference to the patentability of at least one claim.