A failure to register the maximum allowed number of selections for a race or ballot issue.
a ballot for which no presidential vote was recorded
a ballot on which no vote for president was detected by counting machines
a ballot where both a machine count and a hand count fail to detect a vote for any presidential candidate
a vote for fewer than permitted, such as voting for no candidate for President
a vote that was intended to be cast, but was not counted because the machine could not read any vote on the ballot