diff --git a/gdtf-spec.md b/gdtf-spec.md
index 31ee04c..5e8ffa4 100644
--- a/gdtf-spec.md
+++ b/gdtf-spec.md
@@ -518,9 +518,9 @@ currently defined XML attributes of the wheel slot are specified in
 |----|----|----|
 | Name               | [String](#user-content-attrtype-string )        | The name of the wheel slot                                                                                                                                                                                                                                                                                                 |
 | Color              | [ColorCIE](#user-content-attrtype-colorcie )   | Color of the wheel slot, Default value: {0.3127, 0.3290, 100.0 } (white) For Y give relative value compared to overall output defined in property Luminous Flux of related Beam Geometry (transmissive case).                                                                                                                     |
-| Filter             | [Node](#user-content-attrtype-node )       | Optional. Link to filter in the physical description; Do not define color if filter is used; Starting point: Filter Collect                                                                                                                                                                                                       |
+| Filter             | [Node](#user-content-attrtype-node )       | Optional. Link to filter in the physical description, Starting point: Filter Collect                                                                                                                                                                                                       |
 | MediaFileName | [Resource](#user-content-attrtype-resource ) | Optional. PNG file name without extension containing image for specific gobos etc. <br />- Maximum resolution of picture: 1024x1024<br />- Recommended resolution of gobo: 256x256<br />- Recommended resolution of animation wheel: 256x256<br />These resource files are located in a folder called `./wheels` in the zip archive. Default value: empty. |
-| SpecialFunction    | [Enum](#user-content-attrtype-enum )   | Defines special function of the Slot. Currently defined values are "None", "Open" - the slot is not affecting the beam, "Closed" - the slot is completely blocking the beam. Default value is "None". |
+| BeamInfluence      | [Enum](#user-content-attrtype-enum )   | Optional. Describes how the slot is affecting the beam. Currently defined values are "Open" - the slot is not affecting the beam, "Closed" - the slot is completely blocking the beam.|
 </div>
 
 As children the attribute node can have a list of [Prism
@@ -542,8 +542,8 @@ an AnimationSystem it has to have one child called
 [AnimationSystem](#user-content-animation-system).
 
 The [attribute](#annex-a-normative-attribute-definitions) of a parent channel
-function of the linked channel set defines which XML attributes of a wheel slot
-should be utilized and in what order of importance:
+function in the linked channel set defines which XML attributes of a wheel slot
+should be used and in what order of importance:
 
 | GDTF Attribute Name | Utilized XML attribute                                      |
 |----|----|