Modifies the Rights Identifiers attribute of a given X25 Relay
    Client instance to include at least the specified identifier
    name or names.

    add  [node  node-id] x25 relay client client-name -
          rights identifiers {simplename[,simplename...]}

    Rights Identifiers

    Default: No rights     Value: Set of simple names
    identifiers

    Set of rights identifiers that this client possesses. It is used
    when placing the outgoing call.