diff --git a/Documentation/networking/dccp.txt b/Documentation/networking/dccp.txt
index 610083f..a203d13 100644
--- a/Documentation/networking/dccp.txt
+++ b/Documentation/networking/dccp.txt
@@ -140,10 +140,11 @@
 	Whether or not to send Ack Vector options (sec. 11.5).
 
 tx_ccid = 2
-	Default CCID for the sender-receiver half-connection.
+	Default CCID for the sender-receiver half-connection. Depending on the
+	choice of CCID, the Send Ack Vector feature is enabled automatically.
 
 rx_ccid = 2
-	Default CCID for the receiver-sender half-connection.
+	Default CCID for the receiver-sender half-connection; see tx_ccid.
 
 seq_window = 100
 	The initial sequence window (sec. 7.5.2).