doc/mgmt-api: Add Set Appearance command specification
diff --git a/doc/mgmt-api.txt b/doc/mgmt-api.txt
index 2b8a81d..0cc747a 100644
--- a/doc/mgmt-api.txt
+++ b/doc/mgmt-api.txt
@@ -2885,6 +2885,31 @@
 				Invalid Index
 
 
+Set Appearance Command
+======================
+
+	Command Code:		0x0042
+	Controller Index:	<controller id>
+	Command Parameters:	Appearance (2 Octets)
+	Return Parameters:
+
+	This command is used to set the appearance value of a controller.
+
+	This command can be used when the controller is not
+	powered and all settings will be programmed once powered.
+
+	The value of appearance will be remembered when switching
+	the controller off and back on again. So the appearance only
+	have to be set once when a new controller is found and will
+	stay until removed.
+
+	This command generates a Command Complete event on success
+	or a Command Status event on failure.
+
+	Possible errors:	Invalid Parameters
+				Invalid Index
+
+
 Command Complete Event
 ======================