Ballot access rules, called nomination rules outside the United States, regulate the conditions under which a candidate or political party is entitled either to stand for election or to appear on voters' ballots. The criterion to stand as a candidate depends on the individual legal system, however they may include the age of a candidate, citizenship, endorsement by a political party and profession. Legal restrictions, such as those based around competence or moral aptitude, can be used in a discriminatory manner. Restrictive and discriminatory ballot access rules can impact the civil rights of candidates, political parties and voters.