diff --git a/qapi/block-core.json b/qapi/block-core.json
index f525b04..7873084 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1721,6 +1721,10 @@
 #
 # Creates a new block device.
 #
+# This command is still a work in progress.  It doesn't support all
+# block drivers, it lacks a matching blockdev-del, and more.  Stay
+# away from it unless you want to help with its development.
+#
 # @options: block device options for the new device
 #
 # Since: 1.7
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 7f68760..3a42ad0 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3636,6 +3636,10 @@
 
 Add a block device.
 
+This command is still a work in progress.  It doesn't support all
+block drivers, it lacks a matching blockdev-del, and more.  Stay away
+from it unless you want to help with its development.
+
 Arguments:
 
 - "options": block driver options