"A" Means "One or More" Unless Clear Intent to Limit to One

In Baldwin Graphic Systems v. Siebert (January 15, 2007), the Federal Circuit reiterated that
the indefinite article ‘a’ or ‘an’ in patent parlance carries the meaning of ‘one or more’ in open-ended claims containing the transitional phrase "comprising:"

. . . . That "a" or "an" can mean "one or more" is best described as a rule, rather than merely as a presumption or even a convention. The exceptions to this rule are extremely limited: a patentee must "evince[ ] a clear intent" to limit "a" or "an" to "one." Id. The subsequent use of definite articles "the" or "said" in a claim to refer back to the same claim term does not change the general plural rule, but simply reinvokes that non-singular meaning. An exception to the general rule that "a" or "an" means more than one only arises where the language of the claims themselves, the specification, or the prosecution history necessitate a departure from the rule. See, e.g., Abtox Inc. v. Exitron Corp., 122 F.3d 1019 (Fed. Cir. 1997); Insituform Techs., Inc. v. Cat Contracting, Inc., 99 F.3d 1098 (Fed. Cir. 1996).

This record does not contain a clear indication that the applicant departed from the general rule for the article "a." Nothing in the claim language, specification, or prosecution history compels an exceptional reading of "a" in this case. The district court erred by misapplying the term "said fabric roll" later in the claim and the phrase "in intimate contact with the fabric roll" in the specification. Initial Order, slip op. at 8. As noted above, the use of a definite article ("said" or "the") to refer back to an initial indefinite article does not implicate, let alone mandate the singular. Because the initial indefinite article ("a") carries either a singular or plural meaning, any later reference to that same claim element merely reflects the same potential plurality. In grammatical terms, the instances of "said fabric roll" in the claim are anaphoric phrases, referring to the initial antecedent phrase. Because the initial phrase carries no definitive numerosity, the anaphoric phrases do not alter that meaning in the slightest.

Contrary to the district court’s analysis, § 2173.05(e) of the Manual of Patent Examining Procedure (MPEP) does not suggest otherwise. Section 2173.05(e) describes the need, in most cases, for claim terms to have proper antecedent bases:

The lack of clarity could arise where a claim refers to "said lever" or "the
lever," where the claim contains no earlier recitation or limitation of a lever and where it would be unclear as to what element the limitation was making reference. Similarly, if two different levers are recited earlier in
the claim, the recitation of "said lever" in the same or subsequent claim would be unclear where it is uncertain which of the two levers was intended.

MPEP § 2173.05(e). According to the district court, § 2173.05(e) "only strengthens" the exclusively singular nature of "a pre-soaked fabric roll," because "the use of ‘said fabric roll’ implies that the prior reference to ‘a fabric roll’ should be read as a single roll, not one or more rolls, in order to avoid confusion." Initial Order, slip op. 7. To the contrary, MPEP § 2173.05(e) is inapposite because the limitations in claim 32 all relate to proper antecedent bases. Thus, the confusion or indefiniteness problem addressed by § 2173.05(e) does not arise in this claim.

The district court’s reliance on language in the specification to limit "a pre-soaked fabric roll" to a single roll is similarly unavailing. The phrase "disposed around and in
intimate contact with the fabric roll" appears twice in the specification of the Reissue patent, and describes the relationship between the plastic sleeve and the fabric roll. Reissue patent, col.2 ll.22-23, col.3 ll.17-18. This description does not require a single pre-soaked fabric roll. Under the terms of this description, the plastic sleeve could be in intimate contact with multiple fabric rolls, like the plastic wrapping on a package of several hot dogs is in intimate contact with each of the hot dogs, despite the fact that the hot dogs themselves contact each other as well as the packaging. Appellant’s Br. at 13. This description contains no requirement, implicit or explicit, that the plastic sleeve must be in intimate contact with the entire fabric roll. For these reasons, "a pre-soaked fabric roll" as used in claim 32 of the Reissue patent is not limited to a single roll.