A voter may be challenged for cause by a designated observer described in Regulation .18 of this chapter. If a voter is challenged for cause, the challenged voter may vote and shall then place the ballot in an envelope marked only “Secret Ballot”. The “Secret Ballot Envelope” shall next be sealed in a separate envelope marked “Challenged Ballot Envelope”, which identifies on the outside: The identity of the challenged voter; The name of the person making the challenge; and The reason for the challenge. The challenged voter shall then report to the Board representative at the election, who shall allow the challenged voter to place the “Challenged Ballot Envelope” into the container with the regularly cast ballots. If a mail ballot election, the Board representative shall write on the outer envelope the cause of the challenge and set the challenged ballot aside.