diff --git a/gdtf-spec.md b/gdtf-spec.md
index 07ae9da4..5c97e67a 100644
--- a/gdtf-spec.md
+++ b/gdtf-spec.md
@@ -2078,6 +2078,7 @@ currently defined XML attributes of channel function are specified in
 | ModeMaster         | [Node](#user-content-attrtype-node )         | Optional. Link to DMX Channel or Channel Function; Starting point DMX mode.                                                                                   |
 | ModeFrom           | [DMXValue](#user-content-attrtype-dmxvalue ) | Only used together with ModeMaster; DMX start value; Default value: 0/1                                                                                       |
 | ModeTo             | [DMXValue](#user-content-attrtype-dmxvalue ) | Only used together with ModeMaster; DMX end value; Default value: 0/1                                                                                         |
+| ModeDefault        | [DMXValue](#user-content-attrtype-dmxvalue ) | Only used together with ModeMaster; DMX default value for the DMX Channel or Channel Function linked via ModeMaster; Default value: 0/1                                                                                         |
 | DMXProfile         | [Node](#user-content-attrtype-node )         | Optional link to DMX Profile; Starting point: DMX Profile Collect                                                                                             |
 | Min                | [Float](#user-content-attrtype-float )       | Minimum Physical Value that will be used for the DMX Profile. Default: Value from PhysicalFrom                                                                |
 | Max                | [Float](#user-content-attrtype-float )       | Maximum Physical Value that will be used for the DMX Profile. Default: Value from PhysicalTo                                                                  |