diff --git a/configs/features.conf.sample b/configs/features.conf.sample
index 966d008a4ee15ed8c19e8949bab4fb3f7c0fc4ec..30a61b5d2f03c96a622861f36dbaf0e0a3492a7e 100644
--- a/configs/features.conf.sample
+++ b/configs/features.conf.sample
@@ -42,6 +42,10 @@ context => parkedcalls		; Which context parked calls are in
 ;atxfercallbackretries = 2  ; Number of times to attempt to send the call back to the transferer.
                             ; By default, this is 2.
 
+; Note that the DTMF features listed below only work when two channels have answered and are bridged together.
+; They can not be used while the remote party is ringing or in progress. If you require this feature you can use
+; chan_local in combination with Answer to accomplish it.
+
 [featuremap]
 ;blindxfer => #1		; Blind transfer  (default is #)
 ;disconnect => *0		; Disconnect  (default is *)