When you use code generation, this declaration is automatically created in the deployment.h file.
There is an example of a such enum declaration:
typedef enum { node1_partition_secret_outgoing_global = 0, node1_partition_topsecret_outgoing_global = 1, node1_partition_unclassified_outgoing_global = 2, node2_partition_secret_incoming_global = 3, node2_partition_topsecret_incoming_global = 4, node2_partition_unclassified_incoming_global = 5 } pok_port_identifier_t;