-/* Convert 'str_' (as described in the Flow Syntax section of the ovs-ofctl
- * man page) into 'fm'. If 'actions' is specified, an action must be in
- * 'string' and may be expanded or reallocated. */
+/* Convert 'str_' (as described in the Flow Syntax section of the ovs-ofctl man
+ * page) into 'fm' for sending the specified flow_mod 'command' to a switch.
+ * If 'actions' is specified, an action must be in 'string' and may be expanded
+ * or reallocated.
+ *
+ * To parse syntax for an OFPT_FLOW_MOD (or NXT_FLOW_MOD), use an OFPFC_*
+ * constant for 'command'. To parse syntax for an OFPST_FLOW or
+ * OFPST_AGGREGATE (or NXST_FLOW or NXST_AGGREGATE), use -1 for 'command'. */