Ballot Definition File (BDF)
Ballot Definition File (BDF) :
A ballot definition file is a key component of DRE and optical scanning systems. A unique BDF is created for each election and contains all of the details for a given contest, including candidate names, affiliations and other ballot data. The DRE or optical scanner uses the BDF to determine what is displayed on a screen and how ballots are recorded on the system. The counting software on many e-voting systems use BDFs as a key to tally votes. Ballot definition files are often created by third-party vendors or programmers and have been identified as a potential area for human error to enter the system -- or vector for systematic hacking to occur. As a result, ballot definition audits have been the focus of critics of e-voting. VotersUnite.org provides more information in this PDF about ballot definition files
