(1) Not more than 20 calendar days nor less than 10 calendar days prior to any election set by the division, the division shall cause to be prepared and distributed a Notice of Election specifying the date and place thereof; the hours the polls will be open; the classification of employees in the appropriate unit for which the election is to be conducted; rules concerning eligibility to vote; a sample ballot; and such additional information and instruction as the division may consider appropriate. Copies of the Notice of Election and the sample ballot will be sent to all labor organizations appearing on the ballot and to the employer. The employer shall cause copies of the Notice of Election and the sample ballot to be posted for at least five working days prior to the election at work locations where notices are normally posted for the benefit of employees in the appropriate unit. The posting requirement may be modified by mutual agreement of management and the parties appearing on the ballot.