When the voter turns out to vote, he or she may be challenged and required to cast a provisional ballot.

The court also ruled, however, that if a subsequent review concluded that the voter was not entitled to vote in that precinct, then the provisional ballot would not be counted.

It's a new federal law that creates a special category of votes: so-called provisional ballots.

There are concerns, however, the mailing glitch could create confusion with individuals having two ballots or being forced to file provisional ballots on election day.

Challenges to mismatched registrations, which force the use of provisional ballots, must be filed twenty days prior to the election.