diff --git a/UPGRADE.txt b/UPGRADE.txt
index 565a0dd808..ec4c072345 100644
--- a/UPGRADE.txt
+++ b/UPGRADE.txt
@@ -31,6 +31,12 @@ From 10.3 to 10.4:
 
 From 10.2 to 10.3:
 
+* The BLINDTRANSFER channel variable is deleted from a channel when it is
+  bridged to prevent subtle bugs in the parking feature.  The channel
+  variable is used by Asterisk internally for the Park application to work
+  properly.  If you were using it for your own purposes, copy it to your
+  own channel variable before the channel is bridged.
+
 * If no transport is specified in sip.conf, transport will default to UDP.
   Also, if multiple transport= lines are used, only the last will be used.