diff --git a/base_classes/NXobject.nxdl.xml b/base_classes/NXobject.nxdl.xml
index c6ef1ce7d0..0ff8449f09 100644
--- a/base_classes/NXobject.nxdl.xml
+++ b/base_classes/NXobject.nxdl.xml
@@ -64,6 +64,46 @@
             Boolean mask of FIELDNAME values. The value is masked if set to 1.
         </doc>
     </field>
+    <field name="FIELDNAME" type="NX_DTYPE" minOccurs="0">
+        <doc>
+            This is a generic field that defines the attributes that all fields can have.
+        </doc>
+        <attribute name="target" type="NX_CHAR">
+            <doc>
+                This attribute can be used to describe that this field is connected to another field.
+                For links, this must be set to the path of the target of the link.
+
+                Declares the absolute path of an existing field or group.
+
+                Matching regular expression::
+
+                    (/[a-zA-Z_][\w_]*(:[a-zA-Z_][\w_]*)?)+
+
+                For example, given a ``/entry/instrument/detector/polar_angle`` field which is to be
+                connected/linked to /entry/data/polar_angle`` in an ``NXdata`` group, this would be the
+                NeXus data file structure::
+
+                    /: NeXus data file
+                        /entry:NXentry
+                            /data:NXdata
+                                /polar_angle:NX_NUMBER
+                                    @target="/entry/instrument/detector/polar_angle"
+                            /instrument:NXinstrument
+                                /detector:NXdetector
+                                    /polar_angle:NX_NUMBER
+                                        @target="/entry/instrument/detector/polar_angle"
+            </doc>
+        </attribute>
+    </field>
+    <attribute name="target" type="NX_CHAR">
+		<doc>
+			This attribute can be used to describe that this group is connected to another group.
+			For links, this must be set to the path of the target of the link.
+
+			See :ref:`FIELDNAME/@target &lt;/NXobject/FIELDNAME@target-attribute&gt;` for more information
+			how to use this attribute.
+		</doc>
+	</attribute>
 	<field name="identifierNAME" type="NX_CHAR" nameType="partial">
 		<doc>
 			An identifier for a (persistent) resource.
diff --git a/nxdlTypes.xsd b/nxdlTypes.xsd
index b9c972571d..016f60ea38 100644
--- a/nxdlTypes.xsd
+++ b/nxdlTypes.xsd
@@ -454,6 +454,7 @@
 			<xs:documentation>any valid NeXus field or attribute type</xs:documentation>
 		</xs:annotation>
 		<xs:union memberTypes="
+			nxdl:NX_DTYPE
 			nxdl:ISO8601
 			nxdl:NX_BINARY
 			nxdl:NX_BOOLEAN
@@ -472,6 +473,31 @@
 			"/>
 	</xs:simpleType>
 	
+	<xs:simpleType name="NX_DTYPE">
+		<xs:annotation>
+			<xs:documentation>
+			    The union of all nxdl types. To be used if the type cannot be defined.
+			</xs:documentation>
+		</xs:annotation>
+		<xs:union memberTypes="
+			nxdl:ISO8601
+			nxdl:NX_BINARY
+			nxdl:NX_BOOLEAN
+			nxdl:NX_CCOMPLEX
+			nxdl:NX_CHAR
+			nxdl:NX_COMPLEX
+			nxdl:NX_DATE_TIME
+			nxdl:NX_FLOAT
+			nxdl:NX_INT
+			nxdl:NX_NUMBER
+			nxdl:NX_PCOMPLEX
+			nxdl:NX_POSINT
+			nxdl:NX_QUATERNION
+			nxdl:NX_UINT
+			nxdl:NX_CHAR_OR_NUMBER
+			" />
+	</xs:simpleType>
+
 	<xs:simpleType name="NX_CHAR">
 		<xs:annotation>
 			<xs:documentation>