+/*
+* A flow in the network.
+*
+* The meaning of 'in_port' is context-dependent. In most cases, it is a
+* 16-bit OpenFlow 1.0 port number. In the software datapath interface (dpif)
+* layer and its implementations (e.g. dpif-linux, dpif-netdev), it is instead
+* a 32-bit datapath port number.
+*/