Glossary of Election Terms and Acronyms

To help readers understand the election lingo we use throughout our website, we’ve created a glossary of terms and acronyms that we hope to help answer, “What is that?

    The process of examining a voting system to verify and validate the performance of all devices to ensure they meet certification requirements and that the system that was delivered is the same certified system that was purchased or leased.

    Ballot Adjudication is the process of digitally reviewing ballots, cast by mail or at vote centers, that require a clarification/resolution to interpret and capture the voter’s intent. This process is done in conformity with the Secretary of State Uniform Counting Standards.  Ballot adjudication is conducted under the two-person rule. See also, “What is ballot duplication?

    There can be multiple reasons a ballot may require adjudication:

    • Ambiguous (marginal) marks – the voter has not properly or clearly marked any of the voting targets
    • Overvotes – the voter has marked more choices marked than permitted for the contest
    • Undervotes – with the voter has marked fewer choices marked than permitted for the contest
    • Blank Ballots – the voter has left one or more ballot Cards blank, or has not marked any contests
    • Blank Contests – A ballot card where a voter has left one or more contest blank
    • Write-In Choices – the voter has written in the name of a candidate in the write-in space for one or more contest

    An air gap is a physical separation between systems that requires data to be moved by some external, manual procedure, such as by disc, flash drive or other portable media. An air gap is necessary between two systems that (a) are not connected physically and (b) where data transfer is never automated and is only accomplished under human control. Election systems use air gaps intentionally to prevent or control access to a system. The election system cannot be connected to the internet at any time.

    The process of identifying a user, usually by means of multiple factors such as a username and password combination. Election systems use these authentication methods to ensure that only those users with appropriate authority are permitted access.

    The form of ballot you’ve used to cast your vote in an election has changed over history. From voting by marble, to voting on paper, to using computer devices to assist people vote, the advancement of technology has broadened the idea of what a ballot is. The California Elections Code defines “ballot” as any of the following when referring to the election process: 

    (a) The combination of a card with number positions that is marked by the voter and the accompanying reference page or pages containing the names of candidates and the ballot titles of measures to be voted on with numbered positions corresponding to the numbers on the card.

    This is commonly referred to as a, “butterfly ballot.”

    (b) One or more cards upon which are printed the names of the candidates and the ballot titles of measures to be voted on by punching or marking in the designated area.

    Voting by “punching” a hole to indicate your vote were commonly referred to as, “punch-card ballots” and are no longer in use.

    (c) One or more sheets of paper upon which are printed the names of candidates and the ballot titles of measures to be voted on by marking the designated area and that are tabulated manually or by optical scanning equipment.

    This is the most commonly used approved ballot system in California. This system is used in the County of Santa Clara in combination with the ballot described in (d)(2) below.

    (d) (1) An electronic touchscreen upon which appears the names of candidates and ballot titles of measures to be voted on by touching the designated area on the screen for systems that do not contain a paper ballot.

          (2) An electronic touchscreen may qualify as a ballot even for systems that contain paper ballots if the votes are tabulated manually or by optical scanning equipment. This is used in combination with ballot system described in (c), and is beneficial to voters with mobility or vision impairment issues and enables voting independently.

    This term refers to the process of a “human-eye” review and remaking of ballots that are damaged/torn/bent and otherwise unreadable by a machine cannot be read by the ballot counting machine. This important process is done in order to interpret and capture the voter’s intended vote.  Ballot duplication is conducted under the two-person rule.

    See also, “what is adjudication of ballots?”

    A ballot marking device is used as an additional tool to assist voters in marking their paper ballot. A ballot marking device is used in combination with a paper ballot and optical scanning equipment, where the voter uses the ballot marking device to make their vote selections, prints their ballot while in the voting booth, and then places their ballot through the optical scanning equipment for the ballot to be tabulated.

    The County of Santa Clara’s ballot marking device consists of a 19-inch touch sensitive screen that is used to display the official ballot. The voter may choose to display or hear their ballot in a language provided by the Registrar of Voters. The ballot displayed on screen can be marked by hand-touch or by using an alternative assistive device of their own, such as pedals or sip-and-puff.

    Another type of ballot marking device can be the Remote Accessible Vote by Mail System.

    See below, “What is an electronic touchscreen or touch screen voting machine?

    A blank ballot is one on which the voter has not made any mark(s) in any of the voting position target areas (bubbles), or one which has been marked with a pen or pencil that cannot be read by the machine, or one which has been consistently marked outside of the voting position target area on the ballot so the scanner cannot see it.

    Chain of custody means documenting each time items change hands. For example, each time a piece of voting equipment moves from the vendor to the State for testing, from the State back to the vendor after certification, and then from the vendor to the elections official, and so on, this exchange is documented by capturing the name and serial number of the equipment and the date, time and name of the people who are exchanging it. Chain of custody must also follow the two-person rule.

    When used in relation to administering an election, a “district,” includes any regional agency that has the power to tax, to regulate land use, or to condemn and purchase land that is governed by elected officials who have the authority to call an election. Examples may be the State of California, the County of Santa Clara, the City of San Jose, the Campbell Union School District, the Santa Clara Valley Water District, etc. Voters who reside within the legal boundaries of the regional agency or district have the right to vote on candidates and measures the regional agency or district has placed on the ballot.

    You can find a list of the elected representatives in elective districts within Santa Clara County on our website under the “Candidates & Measures” pull down menu and selecting the List of Officeholders. You may look up your own election districts and members by selecting, “Look Up Your District” under our Popular Services link on our home page.

    See also, “What is an electoral jurisdiction?”

    Counties who have adopted the Voter’s Choice Act (VCA) must propose an Election Administration Plan (EAP), which is a detailed plan on the conduct of elections under the VCA. Visit our website for more information about and the most current version of the Election Administration Plan.

    When used in relation to election administration, the term “electoral jurisdiction,” means the physical limits of the agency or district area within which the voters reside who are qualified to vote for the officer or measure on the ballot. This can mean the boundaries of a state, county, city, school or special district or agency, or any subdivided area or division within.

    See also, “What is a district?”

    This is a voting system that uses an electronic device with a screen that reflects the names of candidates and ballot titles of measures to be voted, where the voter marks their ballot choices by touching the designated area on the screen.  This system may be used in conjunction with a paper ballot that is printed and cast on a separate machine, as is the system in use in the County of Santa Clara, or may include a voter verifiable paper cast vote record for the voter to review their ballot before it is cast electronically.

    A touch screen voting machine is also known as a direct recording electronic device, or DRE, that was first used widely under the Help America Vote Act accessibility requirements as it enables a voter with physical or vision difficulties to vote independently. California election laws mandated that any county using a touch screen voting machine, or DRE, must have a voter verifiable paper record of their votes that they can review and approve before their ballot is electronically cast. This paper record is also used to audit and verify the election results obtained from the system. This system is not in use in the County of Santa Clara.

    See also "What is a touchscreen voting machine?"

    An Election Management System (EMS), or also called an Election Information Management System (EIMS). The complete database containing the historical list of registered voters, the elective districts and political subdivisions contained within Santa Clara County, candidate and elected official data and forms, vote by mail information, and other items related to an election.

    Encrypted data means data is “translated” into another form, or code, so only people with access to the secret password or key can read it.

    Encryption denies access to the receiver of the message unless it can be decrypted with the secret password or key, which turns the message into plain text or another usable format. Voting systems can encrypt data within its components before the data is transmitted to other devices.

    Escrow generally refers to the process when items are being held by a third party, on behalf of other transacting parties, where the third party has no interest in those items being held. Under California Election Law, escrow facilities serve as an independent third party that give the Secretary of State direct access to the exact versions of software and firmware that have been approved for use in California. All voting system vendors, Remote Accessible Vote by Mail system, and Election Management System vendors are required to do this.


    Click HERE for more information on California’s Escrow Facility Requirements.


    A facsimile ballot is an exact duplicate of an official ballot, except that is it not available as an or printed on official ballot paper and cannot be used to cast a vote or be tabulated by machine. A facsimile ballot is used by voters who may need additional language assistance to understand their official ballot that is not printed in their native language.

    A firewall refers to a network security device (a router in a computer network) that monitors incoming and outgoing network traffic (applications and users) and allows or blocks traffic based on specific security rules. Firewalls are key stopping points for data coming in or leaving the network and establish a barrier between known trusted networks and untrusted networks, such as the Internet.

    An marginal mark, also referred to as an ambiguous mark, can be a mark outside of the intended vote target area (the circle the voter is to complete), marks that are too light or use of ink other than blue or black that cannot be read (such as red or green, or yellow highlighter), marking with a check-mark, X, or a partially filled or overfilled vote target. A marginal mark is often unreadable by the ballot counting machine and are separated out from other voted ballots for adjudication by no less than two-people.

    See also, “What is a stray mark on a ballot?”

    A security process that requires the user to provide a minimum of two different pieces of information to identify them as an authorized user. It makes it harder for attackers to gain access to a system, account, data, etc. as it requires more information to pass the authentication check.

    A user may be required to provide two or more of the following: something you know (e.g., Password or PIN), and/or something you have (e.g., a security token device or program that generates a one time “key”), and/or something that identifies who you are (e.g., name, email, biometrics).

    An overvote occurs when the voter selects too many options than allowed in a contest. For example, a school district may have three governing member offices on the ballot, directing the voter to, “Vote for not more than three” candidates. The voter “overvotes” this contest if they complete the circle next to the name of more than three different candidates. All other properly marked contests on the voter’s ballot will be counted. The overvoted contest cannot be counted as the voter’s intent is unclear.

    See also, “What is an undervote?

    A penetration test, also known as a pen test or pentest, is a planned and simulated cyberattack done in order to improve a system’s security. The intent is to breach a computer system to find things that must be corrected. This should not be confused with a vulnerability assessment.

      Pre-LAT is a term, or acronym, that refers to the pre-election logic and accuracy tests conducted on all voting equipment prior to use in any election. This is a series of tests done on each piece of voting equipment in order to determine the accuracy of the systems’ computer vote counting and tabulating programs.  

      Under California Election law, a “recount” is the activity of recounting the number of ballot cards cast and retallying votes to confirm the results of the election are accurate.

      Redistricting refers to the process of redrawing political district lines in an effort to “equalize” the number of voters in elective districts (federal, state and local). Redistricting occurs every 10 years and is based on the results of the decennial US Census.

      Visit our page on Redistricting for additional Frequently Asked Questions about the process.

      This Remote Accessible Ballot Marking System or device means a mechanical, electromechanical, or electronic system and its software that is used by a voter with disabilities or a military or overseas voter to mark an electronic copy of their Vote by Mail ballot. The voter then prints their paper ballot, places it inside the blue Vote by Mail return envelope to be returned to the elections official. A remote accessible vote by mail system shall not be connected to a voting system at any time.

      A residual vote is a vote that could not be counted or allocated to a candidate or ballot measure due to the inability to determine the voter’s intent if the contest was clearly overvoted or undervoted.

      Under the California Elections Code, this term refers to a post-election process that involves hand-to-eye, human inspection of ballots in such a manner that if a full manual tally of all the ballots cast in the contest would show different outcomes than the results reported by the voting system, there is at most a five percent chance that the post-election process will not lead to such a full manual tally. If this post-election process does lead to a full manual tally, the winner or winners according to that full manual tally replace the winner or winners as reported by the voting system if they differ.

      Risk-limiting audits provide statistical assurance that election outcomes are correct by manually examining portions of paper ballots or voter-verifiable paper records. California Counties may be permitted to conduct a “risk-limit audit,” starting with the March 3, 2020 Presidential Primary Election in place of the manual tally required before the election can be certified.

      In terms of an election, “software” includes all programs, voting devices, cards, ballot cards or papers, operating manuals or instructions, test procedures, printouts, and other nonmechanical or nonelectrical items necessary to the operation of a voting system.

      In general, a source code is the version of a computer program in which the programmer’s original statements are expressed in a source language which must be compiled or assembled and linked into equal machine-readable object code, resulting in the executable software program. For purposes of elections escrow, this applies to voting system source code, ballot marking system source code, and election management system source codes.

      A stray mark can be an accidental hesitation mark made when a voter has rested their pen on the ballot paper leaving a mark, or a mark left by dragging their pen across the ballot creating a line near the vote target area. A stray mark outside of a vote target area is not detected by the ballot counting machine.

      See also, “What is a marginal or ambiguous mark on a ballot?”

      Tamper evident makes unauthorized access to the protected object easily detected. Tamper evident seals and security labels are often used to detect tampering of containers, ballot boxes, and access points to election systems. When removed, the seal will show tamper evidence by self-destructing, leaving the word “VOID” or “OPENED” to indicate that the seal has been broken. This type of tamper evident seal is referred to as holographic or prism and is extremely difficult to replicate.

      Tamper-evident designs have been a feature of letters since ancient times, often using wax, clay, or metal seals to signify that the letter had not been opened since it was written. For example, unique to the person who owned them, an old signet ring could be pressed into the hot wax seal forming a type of signature, or mark, which could not be easily duplicated by somebody attempting to re-seal the letter.


      A touch screen voting machine is also known as a direct recording electronic device, or DRE, that was first used widely under the Help America Vote Act accessibility requirements as it enables a voter with physical or vision difficulties to vote independently. California election laws mandated that any county using a touch screen voting machine, or DRE, must have a voter verifiable paper record of their votes that they can review and approve before their ballot is electronically cast. This paper record is also used to audit and verify the election results obtained from the system. This system is not in use in the County of Santa Clara.

      See also, “What is an electronic touch screen or touch screen voting machine?


      According to the U.S. Government Accountability Office (GAO), when on the subject of a trusted build: “The voting system's source code is converted to executable code in the presence of at least one VSTL representative and one manufacturer representative, using security measures to ensure that the executable code is a verifiable and faithful representation of the source code. This demonstrates that (1) the software was built as described in the technical documentation, (2) the tested and approved source code was actually used to build the executable code on the system, and (3) no other elements were introduced in the software build. It also serves to document the configuration of the certified system for future reference.


      In general, this means that no less than two people must be included in the procedure. While not defined by law, the “two-person rule” has become a best practice for California election officials. The Santa Clara County Registrar of Voters employs the two-person rule to the entire balloting process, including retrieval and processing of Vote by Mail ballots, and Provisional and Conditional Voter ballots in addition to all voting equipment and official supplies from Vote Centers. The two-person rule often also includes documented chain of custody.


      An undervote occurs when the voter marks fewer choices than they are allowed in a contest. For example, a school district may have three offices on the ballot, directing the voter to, “Vote for not more than three” candidates. The voter has “undervoted” this contest if they did not vote for up to three different candidates, voting for just one or two candidates instead. This contest is counted.

      See also, “what is an overvote?


      A voting position target area refers to that space on the ballot adjacent to each candidate or measure, or that area of the ballot, specifically designated to record the voter's choice for that contest. The term applies to all types of voting position targets on ballots, regardless of what form they may take, including, but not limited to, rectangle, oval, circle, square, hole punch, cross punch, slotting and open arrow.


      As defined in the California Elections Code, a “Vote by mail ballot drop box” is a secure container established by the county or city and county elections official where a voter can deposit their Vote by Mail ballot and return it directly to the elections official.

      A “Vote by mail ballot drop-off location” is a location set up by the elections official where a secure vote by mail ballot drop box is located.

      Vote by Mail ballot drop boxes and drop-off locations are considered a voting location under the rules of “electioneering,” meaning campaigning or soliciting a voter within 100 feet from the drop box while a voter is returning their ballot is prohibited.


      A vote center is a larger polling place that is capable of permitting any registered voter to receive and cast a ballot, regardless of their assigned precinct. Prior to the 2020 elections, Santa Clara County voters would be assigned a specific voting location, called a polling place, based on their residential address and neighborhood precinct. Polling places were only equipped to provide voting services to voters who were assigned to that location, and any other voter would be redirected to their assigned voting location or be provided a provisional ballot.


      The Voter’s Choice Act, also known as VCA, was introduced as State Senate Bill 450 and approved by the Governor in 2016 that allows certain counties to conduct their elections by mailed ballot, as long as they meet certain conditions. The Registrar of Voters has developed a webpage on the Voter’s Choice Act to help the voters in Santa Clara County better understand and participate in the election process.

      For more information on the Voter’s Choice Act law, see Sections 4005 - 4006 of the California Elections Code.


      The term, “Votes Cast” is used to reflect the total number of ballots that were cast in the particular election contest. 

      “Votes Cast” is different than “Voter Turnout,” as it is used to describe the ballots cast in a particular contest (like mayor or state assembly), whereas “Voter Turnout” is typically used to describe the total number of voters who cast a ballot in the entire election. There may be a difference in the “Votes Cast” for the US Senate candidate contest than there is total “Voter Turnout” for the entire election. 

      The number reflected in the column, “Votes Cast” may also differ from the number listed in the “Total Votes” column, where a voter eligible to vote in a particular contest in the election may choose to skip a contest but still cast their ballot. For example, Voter A casts a ballot in the election, which increases the number listed in the “Votes Cast” column, but that voter chose to skip voting on the contest and did not mark any candidate name, therefore, that would not affect the number listed in the “Total Votes,” column of the Statement of the Vote.


      Voter turnout simply refers to the total number of people who participated in the election and cast a ballot. The total turnout would be the total number of voters, which can also be broken down and reflected as Vote by Mail voter turnout and voters who turned out to vote in person.

      It is often reflected in percentages, such as, “…voter turnout at the June Election was 80%” and is the result of calculating the total number of voters who are recorded as having voted with the total number of eligible voters at the election to determine the percentage of voters that turned out or cast a ballot.


      The Voting Systems Test Laboratories (VSTL) is a branch of the Election Assistance Commission (EAC) required under the Help America Vote Act (HAVA) that provides accreditation and revocation of accreditation of independent, non-federal laboratories that are qualified to test voting systems under Federal standards.


      Vulnerability assessment refers to the process of identifying risks and weaknesses in computer networks, systems, hardware, applications, and other parts of the information technology system. These tests are critical in helping protect systems and data from unauthorized access and data breaches as they provide security teams with the information they need to analyze and prioritize corrective actions.

      Click HERE for more information on the Registrar of Voters Election Administration Plan, including a Glossary of Terms and Acronyms relating to elections in general (see “Appendix A”).


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