diff --git a/include/osmocom/msc/call_leg.h b/include/osmocom/msc/call_leg.h
index 61107ee..d8380f5 100644
--- a/include/osmocom/msc/call_leg.h
+++ b/include/osmocom/msc/call_leg.h
@@ -34,6 +34,7 @@
 	/* Array indexed by enum rtp_direction. */
 	enum mgcp_connection_mode crcx_conn_mode[2];
 
+	/* Events dispatched to the parent fi, see call_leg_alloc() doc. */
 	uint32_t parent_event_rtp_addr_available;
 	uint32_t parent_event_rtp_complete;