ff_type: ff_cluster
FF cluster features represent an aggregate consisting of any number of features. The extid of all features within a Cluster must be the same.
Cluster features may have the following special attributes associated with them.
| Attribute Name | Description | 
|---|---|
| ff_down_cluster_link | If this feature is linked to members of a cluster as the parent, this attribute will be present. Range: Yes | 
| ff_down_cluster_ptr{} | If this feature is linked to members of a cluster as the parent, this list attribute will contain the creation numbers of the members of the cluster. Range: Integer |