Illustration in 2D of the assignment of void candidates to families (voids). We show voids that have already been identified {V_i,  V_j,  V_k,  V_l}, with both V_k and V_l having more than one member. The centers of each member in a family are inside the radius of another member belonging to a previous generation of the same family (we highlight this by showing the center of the family members, except for the very first detected member of each family). Blue circles denote void candidates and blue shades represent their cores (which correspond to 70% of the candidate’s radius).