Primary definition
Mark in a contest selection position of a paper ballot that cannot be detected as readable or marginal by a scanner and requires human adjudication.
Also known asunreadable mark · indiscernible mark · ambiguous mark · marginal mark · undetectable mark
2 sources cited4 related termsReviewed Aug 10, 2026
— EAC Glossary of TermsView source
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EAC
U.S. Election Assistance Commission
High consensus
Mark in a contest selection position of a paper ballot that cannot be detected as readable or marginal by a scanner and requires human adjudication.
EAC Glossary of Terms · 2024
Cite this term
Permanent URL · stable across revisions
Election Security Glossary. (2026). Machine Unreadable Mark. In Election Security Glossary. Retrieved August 24, 2026, from https://electionsecurityglossary.com/glossary/machine-unreadable-mark
Sources
2 cited · last checked Aug 10, 2026
01
EAC Glossary of Terms
EAC Glossary of Terms
High consensus
02
NIST Election Glossary
NIST Election Glossary
High consensus
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