If it shall be determined by the City Clerk that such petition has been signed by the required number of electors of the city, nominating such person for such office, it shall be the duty of the City Clerk to place such name on the appropriate city election ballot. Incumbency shall not be indicated unless required by law. Any candidate may withdraw by filing a signed statement of request with the City Clerk not later than 4:00 p.m. local time on Friday following the filing deadline for the original petition. Within five days after the filing of a nominating petition, the election authorities shall notify the candidate whether or not it satisfies the requirements prescribed by this Charter. If a petition is found insufficient, the election authorities shall return it immediately to the person who filed it with a statement certifying wherein it is found insufficient. Within the regular time for filing petitions, such a petition may be amended and filed again as a new petition or a different petition may be filed for the same candidate. The election authorities shall keep on file all petitions found sufficient at least until the expiration of the term for which the candidates are nominated in those petitions.