When the intrinsic evidence provides sufficient guidance in informing a proper claim construction, extrinsic evidence need not be considered. Be mindful of any narrower characterizations you make in the specification, claims, and prosecution history, and ask yourself if they are absolutely necessary.
Background / Facts: The patent here is directed to a computer filing system for accessing files and data according to user-designated criteria. In particular, the invention allows a user to define categories for files stored in a computer system, edit those categories as they are used, label each file with all applicable categories, and link categories in user-definable ways. In this regard, the claims recite the use of a “category description,” which comprises a “descriptive name.” The accused product also uses categorizations but its entries are not names in the grammatical sense, instead consisting only of a series of numerical identifiers.
Issue(s): Whether the “category description” requires an alphabetic descriptive name and therefore excludes names composed solely of nonalphbetic characters, e.g., consisting solely of numbers.
Holding(s): Yes. The patentee relied mainly on extrinsic evidence to show that a “category description” and “descriptive name” could be reasonably understood to encompass purely numerical identifiers of a given category. The court, however, noted poignantly that the intrinsic evidence distinguishes between alphanumeric and purely numeric identifiers, with the “category description,” although it may be associated with a numeric “category description identifier,” is itself an alphanumeric identifier. “[T]he claim language and the specification distinguish between ‘category description,’ which comprises of ‘descriptive names’ and ‘category description identifiers,’ which preferably comprises numerical identifiers. Nothing in the prosecution history alters this conclusion. Accordingly, the intrinsic evidence supports a construction where a ‘category description’ requires information that must include, but which is not limited to, an alphabetic descriptive name.” Stopping the analysis here, the court concluded that “[t]he intrinsic evidence provides sufficient guidance in construing ‘category description,’ and as a result, Speedtrack’s references to extrinsic evidence need not be considered.”