When you use code generation functionnalities, 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 = 0,
node1_partition_topsecret_outgoing = 1,
node1_partition_unclassified_outgoing = 2,
invalid_local_port = 3
} pok_port_local_identifier_t;