diff --git a/Changelog.md b/Changelog.md
index d16f653..54aed0e 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -10,8 +10,8 @@ The following is a brief summary of changes in the current draft version (2.5).
 The above changes mean that each of position/energy/time/polarization objects have one mandatory field and 
 queries with something like `Plane.position.bounds is not null` can be used to detect if the object is present.
 
-- add `ArtifactDescription` entity
-- add `Artifact.descriptor` to support providing descriptions with links (eg in a DataLink output)
+- add `ArtifactDescription` entity to support providing descriptions with links (eg in a DataLink output)
+- add `Artifact.descriptionID` to refer to a shared `ArtifactDescription`
 
 ## radio support
 For radio observations, many properties such as field-of-view, spatial and spectral resolution are dependent on frequency. Modern, wideband facilities can have large frequency-dependent variation in these properties within a single observation.
diff --git a/src/main/resources/CAOM-current-vodml.xml b/src/main/resources/CAOM-current-vodml.xml
index c827e5c..f7f6d84 100644
--- a/src/main/resources/CAOM-current-vodml.xml
+++ b/src/main/resources/CAOM-current-vodml.xml
@@ -1062,6 +1062,18 @@
                     <maxOccurs>-1</maxOccurs>
                 </multiplicity>
             </attribute>
+            <attribute>
+                <vodml-id>Artifact.descriptionID</vodml-id>
+                <name>descriptionID</name>
+                <description>identifier for an ArtifactDescription entity (new in CAOM-2.5)</description>
+                <datatype>
+                    <vodml-ref>ivoa:anyURI</vodml-ref>
+                </datatype>
+                <multiplicity>
+                    <minOccurs>0</minOccurs>
+                    <maxOccurs>1</maxOccurs>
+                </multiplicity>
+            </attribute>
             
             <composition>
                 <vodml-id>Artifact.parts</vodml-id>
@@ -1077,6 +1089,39 @@
             </composition>
         </objectType>
 
+        <objectType>
+            <vodml-id>ArtifactDescription</vodml-id>
+            <name>ArtifactDescription</name>
+            <description>shared and referenceable description of an artitfact (NEW in CAOM-2.5)</description>
+            <extends>
+                <vodml-ref>caom2:CaomEntity</vodml-ref>
+            </extends>
+            <attribute>
+                <vodml-id>ArtifactDescription.uri</vodml-id>
+                <name>uri</name>
+                <description>logical identifier for this description</description>
+                <datatype>
+                    <vodml-ref>ivoa:anyURI</vodml-ref>
+                </datatype>
+                <multiplicity>
+                    <minOccurs>1</minOccurs>
+                    <maxOccurs>1</maxOccurs>
+                </multiplicity>
+            </attribute>
+            <attribute>
+                <vodml-id>Artifact.description</vodml-id>
+                <name>description</name>
+                <description>description of an artifact</description>
+                <datatype>
+                    <vodml-ref>ivoa:string</vodml-ref>
+                </datatype>
+                <multiplicity>
+                    <minOccurs>1</minOccurs>
+                    <maxOccurs>1</maxOccurs>
+                </multiplicity>
+            </attribute>
+        </objectType>
+
         <objectType>
             <vodml-id>Part</vodml-id>
             <name>Part</name>
diff --git a/src/main/resources/draft-CAOM-2.5.png b/src/main/resources/draft-CAOM-2.5.png
index d8ea512..864443e 100644
Binary files a/src/main/resources/draft-CAOM-2.5.png and b/src/main/resources/draft-CAOM-2.5.png differ
diff --git a/src/uml/CAOM.zargo b/src/uml/CAOM.zargo
index 45b0146..1d747cd 100644
Binary files a/src/uml/CAOM.zargo and b/src/uml/CAOM.zargo differ
diff --git a/src/uml/merge-uml-pngs.sh b/src/uml/merge-uml-pngs.sh
index 4750257..88bda79 100644
--- a/src/uml/merge-uml-pngs.sh
+++ b/src/uml/merge-uml-pngs.sh
@@ -1,10 +1,10 @@
 #!/bin/bash
 
-convert -append \
-	CAOM1core.png \
-	CAOM2datatypes.png \
-	CAOM3wcs.png \
-	CAOM4entities.png \
-	CAOM5vocabularies.png \
+## complete list
+#convert -append CAOM1core.png CAOM2datatypes.png CAOM3wcs.png CAOM4entities.png CAOM5vocabularies.png \
 	draft-CAOM-2.5.png
 
+## only changes
+convert -append CAOM1core.png CAOM4entities.png CAOM5vocabularies.png \
+        draft-CAOM-2.5.png
+