§ 323. Preliminary response to petition
If a post-grant review petition is filed under section 321, the patent owner shall have the right to file a preliminary response to the petition, within a time period set by the Director, that sets forth reasons why no post-grant review should be instituted based upon the failure of the petition to meet any requirement of this chapter.
Pub. L. No. 112-29, § 6(d), 125 Stat. 306 (Sept. 16, 2011)