(a) Social fraternities and sororities. This part does not apply to the membership sororities which are exempt from taxation under section 501(a) of the Internal Revenue Code of 1954, the active membership of which consists primarily of students in attendance at institutions of higher education.
(b) YMCA, YWCA, Girl Scouts, Boy Scouts and Camp Fire Girls. This part does not apply to the membership practices of the Young Men's Christian Association, the Young Women's Christian Association, the Girl Scouts, the Boy Scouts and Camp Fire Girls.
(c) Voluntary youth service organizations. This part does not apply to the membership practices of voluntary youth service organizations which are exempt from taxation under section 501(a) of the Internal Revenue Code of 1954 and the membership of which has been traditionally limited to members of one sex and principally to persons of less than nineteen years of age.