37 CFR § 42.224 - Discovery.

---
identifier: "/us/cfr/t37/s42.224"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "37 CFR § 42.224 - Discovery."
title_number: 37
title_name: "Patents, Trademarks, and Copyrights"
section_number: "42.224"
section_name: "Discovery."
chapter_name: "UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE"
subchapter_number: "A"
subchapter_name: "GENERAL"
part_number: "42"
part_name: "TRIAL PRACTICE BEFORE THE PATENT TRIAL AND APPEAL BOARD"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
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."
regulatory_source: "77 FR 48669, Aug. 14, 2012, unless otherwise noted."
cfr_part: "42"
---


# 42.224 Discovery.

Notwithstanding the discovery provisions of subpart A:

(a) Requests for additional discovery may be granted upon a showing of good cause as to why the discovery is needed; and

(b) Discovery is limited to evidence directly related to factual assertions advanced by either party in the proceeding.