diff --git a/geometry_msgs/msg/TransformStamped.msg b/geometry_msgs/msg/TransformStamped.msg
index d948f0fc..068cbad8 100644
--- a/geometry_msgs/msg/TransformStamped.msg
+++ b/geometry_msgs/msg/TransformStamped.msg
@@ -1,9 +1,13 @@
 # This expresses a transform from coordinate frame header.frame_id
-# to the coordinate frame child_frame_id
+# to the coordinate frame child_frame_id at the time of header.stamp
 #
 # This message is mostly used by the
-# <a href="http://www.ros.org/wiki/tf">tf</a> package.
+# <a href="http://www.ros.org/wiki/tf2">tf2</a> package.
 # See its documentation for more information.
+#
+# The child_frame_id is necessary in addition to the frame_id
+# in the Header to communication the full reference for the transform
+# in a self contained message. 
 
 std_msgs/Header header
 string child_frame_id # the frame id of the child frame