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Cast Vote Records (CVR) Subgroup

READ-ONLY SITE MATERIALS: Historical voting TWiki site (2015-2020) ARCHIVED from

This subgroup is creating a common data format specification for cast vote records (CVRs). The specification supports 3 general use cases:

  1. Interoperable exports of CVRs from devices such as scanners, DREs (direct record electronic), or other devices that create CVRs and perform contest rule post-processing. Resultant interoperable import into tabulators, such as election management systems (EMS), or import into auditing systems, or import into adjudication systems.
  2. Interoperable exports of aggregated collections of CVRs from aggregating devices such as EMS.
  3. Interoperable export of CVRs from adjudication devices.

A JSON schema has been generated from the UML model such that scanners and other devices can export and import CVRs in JSON and validate usage against the schema. It should be straightforward to convert the JSON format to other formats such as comma-separated value.

To support auditing, the model contains the following:

  • Support for digitally-signed exports of CVRs.
  • Support for ballot-level auditing, i.e., there is an identifier that can be linked to an ID (identifier) on the corresponding paper ballot provided the scanner creating the CVR can impress an identifier on the ballot as it is scanned.
  • If the scanner does contest-rule post-processing of the ballot selections, indications of what actions the scanner took, e.g., "voter selection overridden by contest rules".
  • Indications of marginal marks, mark quality/density (if scanner is capable).
  • A CVR can include signed/hashed references to an associated image of the ballot or images of write-ins made by the voter on a paper ballot.
  • Improved handling of multi-sheet ballots so that one can more accurately count the number of multi-sheet ballots scanned even if page 1 or any other page is missing.
  • Capability to include batch IDs or other batch information.
  • Support to include adjustments to vote selections made by adjudicators.

For questions, please contact John P. Wack, chair.

Current Status

The Cast Vote Records Common Data Format Specification Version 1.0 has been published.

doi: 10.6028/NIST.SP.1500-103

Cast Vote Records on GitHub.


Membership in this group is open to all; please add yourself to the membership page and subscribe to the email list, instructions below.

  • Arthur Keller
  • Benjamin Long
  • Chris Hughes
  • Chris Jerdonek
  • Danny Casias CO SoS
  • David Cary
  • dmz free and fair
  • Drew Tinney
  • Ed Smith
  • Harvie Branscomb election quality
  • Herb Deutsch
  • Ian Piper
  • Jay Bagga
  • Jerome Lovato CO SoS
  • Jim Canter
  • Jessi Romero CO SoS
  • Joe Kiniry Free and Fair
  • John Dziurla
  • John McCarthy Verified Voting
  • John Wack
  • Katy Owens-Hubler Democracy Fund
  • Kenneth Bennett
  • Larry Moore ClearBallot
  • Lauren Massa-Lochridge
  • Marko Krstovic
  • Mary Brady
  • Neal McBurnnett Election Audits
  • Pam Ravesi ClearBallot
  • Paul Aumayr MD Election Director
  • P Frichbourg ES&S
  • Ray Lutz Citizens Oversight
  • Ryan Macias EAC
  • Sam Dana
  • Stuart Holmes
  • Tim Halvorsen ClearBallot
  • Tom Caddy Pensec

Email List

The email list for this subgroup is vvsg-cvr [at] (vvsg-cvr[at]list[dot]nist[dot]gov).

To join the list or find more information about list policies and related procedures, please visit the VVSG Working Group Lists page.

How to join working group mailing lists



2017-04-10 - 12:23

CVR_Schema_V1.0-16.json (available in

2017-04-06 - 16:41


2017-03-06 - 17:40


2017-04-06 - 16:41


2017-04-10 - 12:23


2017-03-06 - 17:51

2017-03-06 - 17:51

2017-04-06 - 16:35

2016-09-24 - 18:35

ElectronicBallotProcessFlow.vsd (available upon request)

2017-04-10 - 12:23

ElectronicVotingFlow.vsd (available upon request)

2017-04-10 - 12:23


2016-04-20 - 17:13


2016-09-22 - 19:09


2017-03-06 - 17:40


2017-04-06 - 16:34


2016-04-20 - 17:13

PaperBallotProcessFlow.vsd (available upon request)

2017-04-10 - 12:23


2016-09-24 - 18:28



Voting TWiki Archive (2015-2020): read-only, archived wiki site, National Institute of Standards and Technology (NIST)


This page, and related pages, represent archived materials (pages, documents, links, and content) that were produced and/or provided by members of public working groups engaged in collaborative activities to support the development of the Voluntary Voting System Guidelines (VVSG) 2.0. These TWiki activities began in 2015 and continued until early 2020. During that time period, this content was hosted on a Voting TWiki site. That TWiki site was decommissioned in 2020 due to technology migration needs. The TWiki activities that generated this content ceased to operate actively through the TWiki at the time the draft VVSG 2.0 was released, in February of 2020. The historical pages and documents produced there have been archived now in read-only, static form.

  • The archived materials of this TWiki (including pages, documents, links, content) are provided for historical purposes only.
  • They are not actively maintained.
  • They are provided "as is" as a public service.
  • They represent the "work in progress" efforts of a community of volunteer members of public working groups collaborating from late 2015 to February of 2020.
  • These archived materials do not necessarily represent official or peer-reviewed NIST documents nor do they necessarily represent official views or statements of NIST.
  • Unless otherwise stated these materials should be treated as historical, pre-decisional, artifacts of public working group activities only.
  • NIST does not warrant or make any representations regarding the correctness, accuracy, reliability or usefulness of the archived materials.


This wiki was a collaborative website. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these archived TWiki materials. Further, NIST does not endorse any commercial products that may be mentioned in these materials. Archived material on this TWiki site is made available to interested parties for informational and research purposes. Materials were contributed by Participants with the understanding that all contributed material would be publicly available.  Contributions were made by Participants with the understanding that that no copyright or patent right shall be deemed to have been waived by such contribution or disclosure. Any data or information provided is for illustrative purposes only, and does not imply a validation of results by NIST. By selecting external links, users of these materials will be leaving NIST webspace. Links to other websites were provided because they may have information that would be of interest to readers of this TWiki. No inferences should be drawn on account of other sites being referenced, or not referenced, from this page or these materials. There may be other websites or references that are more appropriate for a particular reader's purpose.


Created August 28, 2020, Updated February 5, 2021