Faulty signatures come down to various factors, including voters not knowing how to sign their name, not updating their voter registrations in time and inconsistent signatures over time.

Handwritten signatures are an outdated way of verifying votes, says VoteAmerica, a political NGO. Thousands of Nevada voters still need to verify mail-in ballots.

More than 10,000 mail-in ballots have been rejected in Nevada, a number the secretary of state said he expects to continue to rise.

States that make such comparisons typically match the voter’s signature on the absentee ballot envelope against signatures in the registrar’s voter database and DMV records. If a mismatch is declared, voters are given the opportunity to “cure” a rejected ballot—in Nevada this year, they have through November 12.

Nevada officials are asking voters – especially young people who don't have a long signature history – to verify their votes are cleared.

Ballots with signature issues need to be "cured," where the voter is contacted to make sure a ballot is theirs. About 15,000 were successfully cured.

Young voters don’t have a long history of voting, right?” Aguilar told NewsNation. “The signature that they have is the signature on their voter registration form and sometimes it’s in a digital form at the DMV.