The meaning of "person" in the AIA, and issues with estoppel are addressed in "Return Mail"

The practical issue in Return Mail v. USPS is seen in the line:


Yet construing
§ 18(a)(1)(B) to allow the government to petition for CBM
review, as we do today, means that the government would
enjoy the unique advantage of not being estopped in the
Claims Court from re-litigating grounds raised during a
CBM review proceeding.



Of waiver, the majority noted:


Return Mail’s
failure to develop any arguments on this issue would
typically constitute waiver. See SmithKline Beecham, 439
F.3d at 1319 (“Our law is well established that arguments
not raised in the opening brief are waived.”); see also Nat.
Res. Def. Council, Inc. v. EPA, 25 F.3d 1063, 1074 (D.C.
Cir. 1994) (“[F]ailure to raise a particular question of
statutory construction before an agency constitutes waiver
of the argument in court.”).

[And see footnote 15]



In dissent, Judge Newman began:


An important threshold issue before the court is
whether the United States and its agency the United
States Postal Service are within the definition of “person”
in § 18(a)(1)(B) of the America Invents Act, and thus
entitled to proceed under that Act. The panel majority
states that the appellant waived the issue because it was
not raised in its opening brief. Maj. Op. at 24–25. However,
matters of jurisdiction are not subject to disposition
by waiver.





Of the "person" issue


The general statutory definition is that a “person”
does not include the United States and its agencies unless
expressly provided. It is at least as reasonable to assume
that Congress, and those seeking the improvements
provided by the America Invents Act, knew that “person”
did not include the United States, lest additional complexities
appear in the path of enactment of the America
Invents Act.



Footnote 1 of the dissent



The panel majority states that in this dissent I
“engage[] in mere speculation that Congress intended to
exclude the government from filing petitions despite the
lack of a record or any indication that it intended this
result.” Maj. Op. 27. I do not speculate as to the meaning
of “person”; its meaning has been defined by Congress for
legislative use. Nor do I speculate as to the decade of
legislative history of the America Invents Act. As Justice
Frankfurter wrote, statutory interpretation “demands
awareness of certain presuppositions.” Some Reflections
on the Reading of Statutes, 47 Colum. L. Rev. 527, 537
(1947). The majority ignores the extensive backdrop of
law and history on which the AIA was enacted.


Related to waiver, Judge Newman wrote:


In addition, “[u]nder certain circumstances, we
may consider issues not previously raised . . . .” Automated
Merch. Sys., Inc. v. Lee, 782 F.3d 1376, 1379 (Fed. Cir.
2015). Such circumstances include whether “the issue
involves a pure question of law and refusal to consider it
would result in a miscarriage of justice” and whether “the
issue presents significant questions of general impact or
of great public concern” or “the interest of substantial
justice is at stake.” Id. (citations omitted). This question
requires resolution.