Patent Claim Punctuation Matters

By: Ashley Sloat, Ph.D.

In Securus Technologies, Inc. v. Global Tel*Link Corp., the Federal Circuit reviewed a claim construction dispute with respect to the following claim from U.S. Patent 7,853,243:
 
1.  A method for restricting access to a public telephone network using a telephone call management system, said method comprising the steps of:
    assigning a first identification number to each of a plurality of potential callers;
    recording a first voice print of at least one potential caller;
    storing said first voice print and said first identification number in a database;
    during each access attempt to said public telephone network by said potential caller:
    prompting said at least one potential caller to input a second identification number;
    recording a second voice print of said at least one potential caller;
    matching said first and second identification numbers;
    comparing said second voice print with said first voice print associated with said first identification number;
    granting said at least one potential caller access to said public telephone network to attempt to place a telephone call if said second voice print matches said first voice print;
    monitoring at least one conversation to detect the presence of a three-way call attempt; and
    recording at least one conversation between said at least one potential caller and a third-party remotely located from said at least one potential caller if said recording is permissible; and
    detecting the presence of predetermined keywords in audio of said at least one conversation.
 
            The segment of the claim of interest to the Federal Circuit is shown in blue above. In particular, the Federal Circuit was tasked with determining whether the step of “during…:” included all of the subsequent steps of just the step of “prompting…;”. The Federal Circuit agreed with Global Tel*Link Corp. interpretation of the claimed feature and held that it was most appropriate to include all of the claimed steps from "prompting" to "monitoring" with the "during" step. 
            What we can learn from this is that punctuation matters in a claim. The intent behind the punctuation can also be augmented using formatting (e.g., indentation), enumeration, or other tricks. We at Aurora tend to use formatting to explicitly define which elements are included in a claimed feature. At least some drawbacks of enumeration are that, when used, it could be read that the steps in the method need to be performed in the order in which they are presented rather than any order that is fitting and/or that the method does not include any additional steps (intrinsic or otherwise) that are not recited.