diff --git a/models/sample/test/like_coords.vo-dml.xml b/models/sample/test/like_coords.vo-dml.xml
index 001f70f..3e0d7eb 100644
--- a/models/sample/test/like_coords.vo-dml.xml
+++ b/models/sample/test/like_coords.vo-dml.xml
@@ -10,7 +10,7 @@
       <title></title>
       <author>Arnold Rots, Mark Cresitello-Dittmar, Omar Laurino</author>
       <version>1.0</version>
-      <lastModified>2024-11-28T11:52:20Z</lastModified>
+      <lastModified>2024-11-29T09:02:40Z</lastModified>
       <import>
         <name>ivoa</name>
         <version>1.0</version>
@@ -1051,5 +1051,17 @@
                    <maxOccurs>1</maxOccurs>
                  </multiplicity>
                </attribute>
+               <composition>
+                 <vodml-id>AnObject.sys</vodml-id>
+                 <name>sys</name>
+                 <description>the system</description>	    
+                 <datatype>
+                    <vodml-ref>coords:GenericSys</vodml-ref>
+                 </datatype>
+                 <multiplicity>
+                   <minOccurs>1</minOccurs>
+                   <maxOccurs>1</maxOccurs>
+                 </multiplicity>
+               </composition>
             </objectType>
 </vo-dml:model>
diff --git a/models/sample/test/like_coords.vodsl b/models/sample/test/like_coords.vodsl
index 4a9dac2..89ed408 100644
--- a/models/sample/test/like_coords.vodsl
+++ b/models/sample/test/like_coords.vodsl
@@ -262,4 +262,5 @@ otype CartesianCoordSpace  -> PhysicalCoordSpace "Spatial domain, three-dimensio
  otype AnObject "example content" {
  	   position:LonLatPoint "the position";
  	   time:MJD "The time";
+ 	   sys: GenericSys as composition "the system";
  } 
\ No newline at end of file
diff --git a/tools/gradletooling/sample/src/test/java/org/ivoa/dm/notstccoords/CoordsModelDbTest.java b/tools/gradletooling/sample/src/test/java/org/ivoa/dm/notstccoords/CoordsModelDbTest.java
index 8fc52ba..abfdc60 100644
--- a/tools/gradletooling/sample/src/test/java/org/ivoa/dm/notstccoords/CoordsModelDbTest.java
+++ b/tools/gradletooling/sample/src/test/java/org/ivoa/dm/notstccoords/CoordsModelDbTest.java
@@ -28,6 +28,7 @@ class CoordsModelDbTest extends AutoDBRoundTripTest<CoordsModel,Long,AnObject> {
   /** logger for this class */
   private static final org.slf4j.Logger logger =
       org.slf4j.LoggerFactory.getLogger(CoordsModelDbTest.class);
+
 private AnObject a;
 
   @Override
@@ -35,6 +36,7 @@ public CoordsModel createModel() {
     // see
     // https://github.com/mcdittmar/ivoa-dm-examples/blob/master/assets/examples/coords/current/instances/astrocoordsys.jovial for jovial version of this test.
     Unit deg = new Unit("deg");
+    Unit kms = new Unit("kms");
     SpaceSys ICRS_SYS =
         new SpaceSys()
             .withFrame(
@@ -62,7 +64,10 @@ public CoordsModel createModel() {
                                         p.lat = new RealQuantity(-16.716116, deg);
                                         p.dist = new RealQuantity(8.6, new Unit("ly"));
                                         p.coordSys = ICRS_SYS;
-                                      }));
+                                      }))
+                              .withVelocity(new CartesianPoint(new RealQuantity(5.0,kms), 
+                                      new RealQuantity(5.0,kms), new RealQuantity(5.0,kms), ICRS_SYS));//IMPL cartesianpoint for a velocity!
+                                
                     }));
     GenericSys SPECSYS =
         new GenericSys()
@@ -73,17 +78,14 @@ public CoordsModel createModel() {
                       f.planetaryEphem = "DE432";
                     }));
 
-
+    SpaceSys GENSYS = null;
 
     // note that this cannot be added directly as it is a dtype...
     LonLatPoint llp = new LonLatPoint(new RealQuantity(45.0, deg), new RealQuantity(15.0, deg), new RealQuantity(1.5, new Unit("Mpc")), ICRS_SYS);
     MJD mjd = new MJD(60310.0, TIMESYS_TT);
-    a = new AnObject(llp,mjd);
+    a = new AnObject(llp,mjd, SPECSYS);
     CoordsModel modelInstance = new CoordsModel();
 
-    modelInstance.addReference(TIMESYS_TT);
-    modelInstance.addReference(SPECSYS);
-    modelInstance.addReference(ICRS_SYS);
     modelInstance.addContent(a);
     
     
@@ -107,9 +109,24 @@ public void testModel(CoordsModel coordsModel) {
      List<AnObject> ts = coordsModel.getContent(AnObject.class);
      assertNotNull(ts);
      assertEquals(1, ts.size());
-     AnObject ts1 = ts.get(0);
-     SpaceSys ss = ts1.getPosition().getCoordSys();
+     AnObject ano = ts.get(0);
+     SpaceSys ss = ano.getPosition().getCoordSys();
      assertNotNull(ss);
+     MJD mjd = ano.getTime();
+     assertNotNull(mjd);
+     TimeSys tcsys = mjd.getCoordSys();
+     assertNotNull(tcsys);
+     TimeFrame tframe = tcsys.getFrame();
+     CustomRefLocation rd = (CustomRefLocation)tframe.getRefDirection();
+     LonLatPoint pos = (LonLatPoint)rd.getPosition();
+     assertEquals(-16.716116, pos.getLat().getValue());
+     GenericSys sys = ano.getSys(); 
+     GenericFrame gframe = sys.getFrame();
+     StdRefLocation gref = (StdRefLocation) gframe.getRefPosition();
+     assertEquals("TOPOCENTER",gref.getPosition());
+     
+     
+     
     
   }
 
diff --git a/tools/gradletooling/sample/src/test/java/org/ivoa/dm/notstccoords/CoordsModelTest.java b/tools/gradletooling/sample/src/test/java/org/ivoa/dm/notstccoords/CoordsModelTest.java
index f533720..22b111b 100644
--- a/tools/gradletooling/sample/src/test/java/org/ivoa/dm/notstccoords/CoordsModelTest.java
+++ b/tools/gradletooling/sample/src/test/java/org/ivoa/dm/notstccoords/CoordsModelTest.java
@@ -77,12 +77,9 @@ public CoordsModel createModel() {
     // note that this cannot be added directly as it is a dtype...
     LonLatPoint llp = new LonLatPoint(new RealQuantity(45.0, deg), new RealQuantity(15.0, deg), new RealQuantity(1.5, new Unit("Mpc")), ICRS_SYS);
     MJD mjd = new MJD(60000.0, TIMESYS_TT);
-    AnObject a = new AnObject(llp, mjd);
+    AnObject a = new AnObject(llp, mjd, SPECSYS);
     CoordsModel modelInstance = new CoordsModel();
 
-    modelInstance.addReference(TIMESYS_TT);
-    modelInstance.addReference(SPECSYS);
-    modelInstance.addReference(ICRS_SYS);
     modelInstance.addContent(a);
     
     
diff --git a/tools/xslt/jpa.xsl b/tools/xslt/jpa.xsl
index b39eb8f..1fd7f1b 100644
--- a/tools/xslt/jpa.xsl
+++ b/tools/xslt/jpa.xsl
@@ -239,7 +239,8 @@
         <xsl:param name="nillable"/>
         @jakarta.persistence.Embedded
         <xsl:variable name="attovers" as="xsd:string*">
-
+              <!-- IMPL - this code is a bit ugly - is attempting to deal with the case where a dataType has a dataType member (quite frequent as base model has quantities)
+              it probably can be refactored to be a bit more recursive -->
                 <xsl:variable name="atv" as="xsd:string*">
                     <xsl:apply-templates select="$models/key('ellookup',current()/datatype/vodml-ref)" mode="attrovercols"><xsl:with-param name="prefix" select="$name"/></xsl:apply-templates>
                 </xsl:variable>