HIERARCHY RULE FOR DEPENDENTS. The choice of enrolling dependents must follow a hierarchy. This means that for married principal member, the spouse must be enrolled first followed by the eldest child, second child and so on. For single principal member, the parents must be enrolled first followed by eldest brother/sister and so on. If the Principal Member is married, his/her parents, brothers or sisters are no longer eligible as Qualified Dependents unless expressly provided for in this Agreement.