diff --git a/docs/source/dataset_metadata.rst b/docs/source/dataset_metadata.rst
index 13d9955..a35d4c0 100644
--- a/docs/source/dataset_metadata.rst
+++ b/docs/source/dataset_metadata.rst
@@ -388,6 +388,7 @@ Each appliance dict has:
 :part_number: (string)
 :gtin: (int) http://en.wikipedia.org/wiki/Global_Trade_Item_Number
 :version: (string)
+:portable: (boolean)
 
 Additional properties are specified for some Appliance Types.  Please
 look up objects in