diff --git a/SDT/schema3.0/etc/domain.rnc b/SDT/schema3.0/etc/domain.rnc
index 0d15caae3f054c90abc3c81fe25a7697386d6769..d0e0df432a6aeb93f47480050d42e4046412b8e4 100644
--- a/SDT/schema3.0/etc/domain.rnc
+++ b/SDT/schema3.0/etc/domain.rnc
@@ -35,15 +35,6 @@ Domain =
       }*
     }?
   }
-DeviceInfos =
-  element DeviceInfos {
-    element DeviceInfo {
-      attribute name { text },
-      attribute optional { xsd:boolean }?,
-      DocDef,
-      DataTypeDef
-    }*
-  }
 Characteristics =
   element Characteristics {
     element Characteristic {
@@ -155,6 +146,6 @@ Events =
       attribute name { text },
       attribute optional { xsd:boolean }?,
       DocDef,
-      Data
+      Data?
     }*
   }
diff --git a/SDT/schema3.0/src/domain.rng b/SDT/schema3.0/src/domain.rng
index df7d6c8989fcf26757ef9f7cec7b7b0504b5087c..9b0b66facd861d5571d9a7cd2534a6f1d22a0e28 100644
--- a/SDT/schema3.0/src/domain.rng
+++ b/SDT/schema3.0/src/domain.rng
@@ -357,7 +357,9 @@
 						</attribute>
 					</optional>
 					<ref name="DocDef"/>
-					<ref name="Data" />
+					<optional>
+						<ref name="Data" />
+					</optional>
 				</element>
 			</zeroOrMore>
 		</element>
diff --git a/SDT/schema3.0/src/domain.xsd b/SDT/schema3.0/src/domain.xsd
index 01e69d3a96d3869b349be8a3f98d18c717a8ceb4..55e3a19d541bc9bdd64661f704fd23d6d5f802e0 100644
--- a/SDT/schema3.0/src/domain.xsd
+++ b/SDT/schema3.0/src/domain.xsd
@@ -66,24 +66,6 @@
       <xs:attribute name="id" use="required" type="xs:Name"/>
     </xs:complexType>
   </xs:element>
-  <xs:element name="DeviceInfos">
-    <xs:complexType>
-      <xs:sequence>
-        <xs:element minOccurs="0" maxOccurs="unbounded" ref="DeviceInfo"/>
-      </xs:sequence>
-    </xs:complexType>
-  </xs:element>
-  <xs:element name="DeviceInfo">
-    <xs:complexType>
-      <xs:sequence>
-        <xs:group ref="DocDef"/>
-        <xs:element ref="DataTypeDef"/>
-      </xs:sequence>
-      <xs:attribute name="name" use="required"/>
-      <xs:attribute name="optional" type="xs:boolean"/>
-      <xs:attributeGroup ref="DataTypeDef"/>
-    </xs:complexType>
-  </xs:element>
   <xs:element name="Characteristics">
     <xs:complexType>
       <xs:sequence>
@@ -283,7 +265,7 @@
     <xs:complexType>
       <xs:sequence>
         <xs:group ref="DocDef"/>
-        <xs:element ref="Data"/>
+        <xs:element minOccurs="0" ref="Data"/>
       </xs:sequence>
       <xs:attribute name="name" use="required"/>
       <xs:attribute name="optional" type="xs:boolean"/>