---
kind: "section"
citation: "37 C.F.R. § 42.23"
title: "37"
number: "42.23"
heading: "Oppositions, replies, and sur-replies."
url: "https://uscodex.org/cfr/37/42.23"
---

# §42.23. Oppositions, replies, and sur-replies.

- (a) Oppositions, replies, and sur-replies must comply with the content requirements for motions and, if the paper to which the opposition, reply, or sur-reply is responding contains a statement of material fact, must include a listing of facts that are admitted, denied, or cannot be admitted or denied. Any material fact not specifically denied may be considered admitted.
- (b) All arguments for the relief requested in a motion must be made in the motion. A reply may only respond to arguments raised in the corresponding opposition, patent owner preliminary response, patent owner response, or decision on institution. A sur-reply may only respond to arguments raised in the corresponding reply and may not be accompanied by new evidence other than deposition transcripts of the cross-examination of any reply witness.

## Notes

### Amendments

[85 FR 79128, Dec. 9, 2020]

### Authority

Authority: 35 U.S.C. 2(b)(2), 3, 6, 21, 23, 41, 134, 135, 143, 153, 311, 312, 314, 316, 318, 321-326, 328; Pub. L. 112-29, 125 Stat. 284; and Pub. L. 112-274, 126 Stat. 2456.

### Source

Source: 77 FR 48669, Aug. 14, 2012, unless otherwise noted.

### Amendments

[85 FR 79128, Dec. 9, 2020]