Editorial Note on Subchapter A of Chapter I
Editorial Note: Part 2 is placed in the separate grouping of parts pertaining to trademarks regulations.

Editorial Note on Subchapter A of Chapter I
Editorial Note: Part 6 is placed in the separate grouping of parts pertaining to trademarks regulations.

Editorial Note on Subchapter A of Chapter I
Editorial Note: Part 7 is placed in the separate grouping of parts pertaining to trademarks regulations.

Editorial Note on Subchapter A of Chapter I
Editorial Note: Part 1 is placed in the separate grouping of parts pertaining to patents regulations.

Editorial Note on Subchapter A of Chapter I
Editorial Note: Part 3 pertaining to both patents and trademarks is placed in the grouping pertaining to patents regulations.

Editorial Note on Subchapter A of Chapter I
Editorial Note: Part 4 is placed in the separate grouping of parts pertaining to patents regulations.

Editorial Note on Subchapter A of Chapter I
Editorial Note: Part 5 is placed in the separate grouping of parts pertaining to patents regulations.

§ 42.51 Discovery. ( a ) *Mandatory initial disclosures.* ( 1 ) *With agreement.* Parties may agree to mandatory discovery requiring the initial disclosures set forth in the Office Patent Trial Practice Guide. ( i ) The parties must submit any agreement reached on initial disclosures by no later than the filing of the patent owner preliminary response or the expiration of the time period for filing such a response. The initial disclosures of the parties shall be filed as exhibits.
( ii ) Upon the institution of a trial, parties may automatically take discovery of the information identified in the initial disclosures.
( 2 ) *Without agreement.* Where the parties fail to agree to the mandatory discovery set forth in paragraph (a)(1), a party may seek such discovery by motion.
( b ) *Limited discovery.* A party is not entitled to discovery except as provided in paragraph (a) of this section, or as otherwise authorized in this subpart. ( 1 ) *Routine discovery.* Except as the Board may otherwise order: ( i ) Unless previously served or otherwise by agreement of the parties, any exhibit cited in a paper or in testimony must be served with the citing paper or testimony.
( ii ) Cross examination of affidavit testimony prepared for the proceeding is authorized within such time period as the Board may set.
( iii ) Unless previously served, a party must serve relevant information that is inconsistent with a position advanced by the party during the proceeding concurrent with the filing of the documents or things that contains the inconsistency. This requirement does not make discoverable anything otherwise protected by legally recognized privileges such as attorney-client or attorney work product. This requirement extends to inventors, corporate officers, and persons involved in the preparation or filing of the documents or things.
( 2 ) *Additional discovery.* ( i ) The parties may agree to additional discovery between themselves. Where the parties fail to agree, a party may move for additional discovery. The moving party must show that such additional discovery is in the interests of justice, except in post-grant reviews where additional discovery is limited to evidence directly related to factual assertions advanced by either party in the proceeding (*see* § 42.224). The Board may specify conditions for such additional discovery.
( ii ) When appropriate, a party may obtain production of documents and things during cross examination of an opponent's witness or during authorized compelled testimony under § 42.52.
( c ) *Production of documents.* Except as otherwise ordered by the Board, a party producing documents and things shall either provide copies to the opposing party or make the documents and things available for inspection and copying at a reasonable time and location in the United States.
[77 FR 48669, Aug. 14, 2012, as amended at 80 FR 28565, May 19, 2015]