diff --git a/src/domain.rng b/src/domain.rng
index 0b2d368393b378bc3d22e6c6efcf4c7f9d6aca2e..ecf4fc72d341c12be552aecc6cf5879a3acbbb8c 100644
--- a/src/domain.rng
+++ b/src/domain.rng
@@ -140,6 +140,9 @@
     <optional>
       <ref name="Actions"/>
     </optional>
+    <optional>
+      <ref name="Data"/>
+    </optional>
     <optional>
       <ref name="Events"/>
     </optional>
@@ -182,6 +185,29 @@
     </element>
   </define>
 
+  <define name="Data">
+    <element name="Data">
+      <zeroOrMore>
+	<element name="DataPoint">
+	  <attribute name="name">
+	    <text/>
+	  </attribute>
+	  <optional>
+	    <attribute name="type">
+	      <ref name="DataType"/>
+	    </attribute>
+	  </optional>
+	  <optional>
+	    <attribute name="writable">
+	      <data type="boolean"/>
+	    </attribute>
+	  </optional>
+	  <ref name="Doc"/>
+	</element>
+      </zeroOrMore>
+    </element>
+  </define>
+
   <define name="Events">
     <element name="Events">
       <zeroOrMore>
diff --git a/src/domain.xsd b/src/domain.xsd
index f6f2a8f164feb540410c0d74b3b4bb651e3672d2..fe3ea3f95672c5eca712801f2bdcc3b4b8eaec27 100644
--- a/src/domain.xsd
+++ b/src/domain.xsd
@@ -115,6 +115,7 @@
       <xs:element minOccurs="0" ref="extends"/>
       <xs:group ref="Doc"/>
       <xs:element minOccurs="0" ref="Actions"/>
+      <xs:element minOccurs="0" ref="Data"/>
       <xs:element minOccurs="0" ref="Events"/>
     </xs:sequence>
     <xs:attribute name="name" use="required"/>
@@ -157,6 +158,21 @@
       <xs:attribute name="type" use="required" type="DataType"/>
     </xs:complexType>
   </xs:element>
+  <xs:element name="Data">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="DataPoint"/>
+      </xs:sequence>
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="DataPoint">
+    <xs:complexType>
+      <xs:group ref="Doc"/>
+      <xs:attribute name="name" use="required"/>
+      <xs:attribute name="type" type="DataType"/>
+      <xs:attribute name="writable" type="xs:boolean"/>
+    </xs:complexType>
+  </xs:element>
   <xs:element name="Events">
     <xs:complexType>
       <xs:sequence>