Inconsistencies in U.S. Antecedent Basis Requirements?

In Energizer Holdings, Inc., et al. v. International Trade Commission, et al. (Fed. Cir. January 25, 2006), the court reversed the Commission's ruling that independent claim 1 and dependent claims 2-7 were invalid for indefiniteness under 35 U.S.C. §112 ¶2, on the ground that the claim term "said zinc anode" lacks antecedent basis in the claim. Claim 1 read as follows

1. An electrochemical cell comprising an alkaline electrolyte, a cathode
comprising manganese dioxide as an active cathode component, and an anode gel comprised of zinc as the active anode component, wherein the cell contains less
than 50 parts of mercury per million parts by weight of the cell and said zinc
anode has a gel expansion of less than 25% after being discharged for 161
minutes to 15% depth of discharge at 2.88A.

The Commission also held that even if "said zinc anode" is construed to have as antecedent the "anode gel comprised of zinc as the active anode component" recited earlier in the claim, the claim would still be indefinite because, as written, it requires that the anode of every cell has been "discharged for 161 minutes to 15% depth of discharge at 2.88A."

According to the Federal Circuit,

Whether this claim, despite lack of explicit antecedent basis for "said zinc
anode," nonetheless has a reasonably ascertainable meaning must be decided in
context. In prosecuting the '709 patent, the examiner made several objections to
the claims, but the claims were not rejected or objected to on the ground of
lack of antecedent basis. In Bose Corp. v. JBL, Inc., 274 F.3d 1354, 1359 (Fed.
Cir. 2001) the court held that despite the absence of explicit antecedent basis,
"If the scope of a claim would be reasonably ascertainable by those skilled in
the art, then the claim is not indefinite." Moreover, we noted in Slimfold that
an antecedent basis can be present by implication. Slimfold, 810 F.2d at 1116.
See Cross Medical Products v. Medtronic Sofamor Danek, 424 F.3d 1293, 1319 (Fed. Cir. 2005).

Neither the Commission nor the Intervenors argued that they did
not understand the intended scope because of the absence of an antecedent. The
Commission erred in holding that the need to construe a claim, or the proffer of
alternative constructions, renders the claim indefinite. A claim that is
amenable to construction is not invalid on the ground of indefiniteness. In
Exxon Research & Engineering, 265 F.3d at 1375, the court stated that "if
the meaning of the claim is discernible, even though the task may be formidable
and the conclusion may be one over which reasonable persons will disagree, we
have held the claim sufficiently clear to avoid invalidity on indefiniteness
grounds." See also Novo Indus., L.P. v. Micro Molds Corp., 350 F.3d 1348, 1353
(Fed. Cir. 2003) (determining whether claim is "amenable to construction");
Honeywell Int’l, Inc. v. Int'l Trade Comm'n, 341 F.3d 1332, 1338 (Fed. Cir.
2003) (a claim is not indefinite because it is hard to construe). Here, it is
apparent that the claim can be construed. In that regard, we conclude that
"anode gel" is by implication the antecedent basis for "said zinc anode." The
Commission's holding of invalidity on the ground of indefiniteness is reversed.

While the Commission's ruling might, at first glance, seem sorely out of step with current prosecution practice, Professor Wegner has pointed out that whether a clear grammatical mistake will be held against a patentee is very often panel dependent. "With a different panel an even less obvious mistake – using 'to' instead of 'at' to describe the heating of a bakery dough to (instead of at) incineration temperatures – led to the nonsensical interpretation of a process to make ruined, incineration particles of dough." See Chef America, Inc. v. Lamb-Weston, Inc., 358 F.3d 1371, 1372 (Fed. Cir. 2004)(Schall, J.). "Neither the fairness/equity ruling in Energizer Holdings (which also differs from PTO holdings) nor the straight forward legal ruling in Chef America is necessarily “right” or “wrong”: But what is wrong is the lack of consistency at the court when it deals with attorney claim drafting mistakes." See also Ex parte Boswell, 1995 WL 1747745 (PTO Bd. App. & Int. 1995); Ex parte Lafferty, 1997 WL 1935437 (PTO Bd. App. & Int. 1997); Ex parte Durrani, 1999 WL 33224340 (PTO Bd. App. & Int. 1999).