diff --git a/SDT/schema4.0/docs/images/Array.png b/SDT/schema4.0/docs/images/Array.png
index 30982dc73b44c1033c96314b66f5df7be8fda1c7..67e06df30855bfc6ec2f888ab5f42aa9eb196a6c 100644
Binary files a/SDT/schema4.0/docs/images/Array.png and b/SDT/schema4.0/docs/images/Array.png differ
diff --git a/SDT/schema4.0/docs/images/Enum.png b/SDT/schema4.0/docs/images/Enum.png
index db3738a8b77db61aefae50fafaec58079d1d0556..4e6f7f822d52bb4fe04458dbba4da72a6d43acfa 100644
Binary files a/SDT/schema4.0/docs/images/Enum.png and b/SDT/schema4.0/docs/images/Enum.png differ
diff --git a/SDT/schema4.0/docs/images/SDT_UML_DataType.png b/SDT/schema4.0/docs/images/SDT_UML_DataType.png
index 113771b84a82d00cff2f78639cabb21f475afa13..e2372f1832206b715ef1e2b4b96e2737b82e53cc 100644
Binary files a/SDT/schema4.0/docs/images/SDT_UML_DataType.png and b/SDT/schema4.0/docs/images/SDT_UML_DataType.png differ
diff --git a/SDT/schema4.0/docs/images/SimpleType.png b/SDT/schema4.0/docs/images/SimpleType.png
index 4a3c7b61e4edad95d5d78220f982bc720484a08a..1e064804a1a894edc46002561870d5602da917d3 100644
Binary files a/SDT/schema4.0/docs/images/SimpleType.png and b/SDT/schema4.0/docs/images/SimpleType.png differ
diff --git a/SDT/schema4.0/docs/images/Struct.png b/SDT/schema4.0/docs/images/Struct.png
index 4e4c9984f6418980683ab633aec15699eee686fd..08a48cb06577bb22e71f1f94627c3643de6cb17e 100644
Binary files a/SDT/schema4.0/docs/images/Struct.png and b/SDT/schema4.0/docs/images/Struct.png differ
diff --git a/SDT/schema4.0/etc/domain.rnc b/SDT/schema4.0/etc/domain.rnc
index 21a15f726dbc14fe14a5efea82d4efe8a3548537..df77d77693698977c9c0030dd2065c7dbe60b0f2 100644
--- a/SDT/schema4.0/etc/domain.rnc
+++ b/SDT/schema4.0/etc/domain.rnc
@@ -29,7 +29,7 @@ PropertiesDef =
       attribute value { text }?,
       attribute semanticURI { xsd:anyURI }?,
       DocDef,
-      SimpleType
+      Simple
     }+
   }
 DataTypeDef =
@@ -38,16 +38,16 @@ DataTypeDef =
     attribute unitOfMeasure { text }?,
     attribute semanticURI { xsd:anyURI }?,
     DocDef,
-    (ExtendDef? | (StructType | ArrayType | SimpleType | EnumType)),
+    (ExtendDef? | (Struct | Array | Simple | Enum)),
     ConstraintsDef?
   }
-StructType = element Struct { DataTypeDef+ }
-ArrayType = element Array { DataTypeDef }
-SimpleType =
-  element SimpleType {
+Struct = element Struct { DataTypeDef+ }
+Array = element Array { DataTypeDef }
+Simple =
+  element Simple {
     attribute type { BasicType }
   }
-EnumType = element Enum { EnumValueDef+ }
+Enum = element Enum { EnumValueDef+ }
 BasicType =
   "integer"
   | "boolean"
diff --git a/SDT/schema4.0/src/domain.rng b/SDT/schema4.0/src/domain.rng
index e5cb20bfca88c90e4a4bd223c48bbb05b7dde87a..b47f23c2b834260d55a1bbb30b657185f2e7a7f0 100644
--- a/SDT/schema4.0/src/domain.rng
+++ b/SDT/schema4.0/src/domain.rng
@@ -87,7 +87,7 @@
 						</attribute>
 					</optional>
 					<ref name="DocDef"/>
-					<ref name="SimpleType" />
+					<ref name="Simple" />
 				</element>
 			</oneOrMore>
 		</element>
@@ -117,10 +117,10 @@
 					<ref name="ExtendDef" />
 				</optional>
 				<choice>
-					<ref name="StructType" />
-					<ref name="ArrayType" />
-					<ref name="SimpleType" />
-					<ref name="EnumType" />
+					<ref name="Struct" />
+					<ref name="Array" />
+					<ref name="Simple" />
+					<ref name="Enum" />
 				</choice>
 			</choice>
 			<optional>
@@ -130,7 +130,7 @@
 	</define>
 
 
-	<define name="StructType">
+	<define name="Struct">
 		<element name="Struct">
 			<oneOrMore>
 				<ref name="DataTypeDef" />
@@ -139,15 +139,15 @@
 	</define>
 
 
-	<define name="ArrayType">
+	<define name="Array">
 		<element name="Array">
 			<ref name="DataTypeDef" />
 		</element>
 	</define>
 
 
-	<define name="SimpleType">
-		<element name="SimpleType">
+	<define name="Simple">
+		<element name="Simple">
 			<attribute name="type">
 				<ref name="BasicType" />
 			</attribute>
@@ -155,7 +155,7 @@
 	</define>
 	
 
-	<define name="EnumType">
+	<define name="Enum">
 		<element name="Enum">
 			<oneOrMore>
 				<ref name="EnumValueDef" />
diff --git a/SDT/schema4.0/src/domain.xsd b/SDT/schema4.0/src/domain.xsd
index a43dbde64a3de638f3826a2f1b62955407cb9acd..a335e8b2514b5f72967fb550d42325252adc2fd2 100644
--- a/SDT/schema4.0/src/domain.xsd
+++ b/SDT/schema4.0/src/domain.xsd
@@ -60,7 +60,7 @@
       <xs:complexContent>
         <xs:extension base="DocDef">
           <xs:sequence>
-            <xs:element ref="SimpleType"/>
+            <xs:element ref="Simple"/>
           </xs:sequence>
           <xs:attribute name="name" use="required" type="xs:Name"/>
           <xs:attribute name="optional" type="xs:boolean"/>
@@ -80,7 +80,7 @@
               <xs:choice>
                 <xs:element ref="Struct"/>
                 <xs:element ref="Array"/>
-                <xs:element ref="SimpleType"/>
+                <xs:element ref="Simple"/>
                 <xs:element ref="Enum"/>
               </xs:choice>
             </xs:choice>
@@ -107,7 +107,7 @@
       </xs:sequence>
     </xs:complexType>
   </xs:element>
-  <xs:element name="SimpleType">
+  <xs:element name="Simple">
     <xs:complexType>
       <xs:attribute name="type" use="required" type="BasicType"/>
     </xs:complexType>
diff --git a/SDT/schema4.0/test/EchonetLiteExamples.xml b/SDT/schema4.0/test/EchonetLiteExamples.xml
index fd411ca72f383e31be7f26b24e0fb7f8bb162268..d5b9773ba1b981222687e0b2c5a83c6c707b1d99 100644
--- a/SDT/schema4.0/test/EchonetLiteExamples.xml
+++ b/SDT/schema4.0/test/EchonetLiteExamples.xml
@@ -15,7 +15,7 @@
 				<DataPoint name="operationStatus" readable="true" writable="true">
 					<Doc>This property indicates the ON/OFF status.</Doc>
 					<DataType>
-						<SimpleType type="boolean" />
+						<Simple type="boolean" />
 					</DataType>
 				</DataPoint>
 			</Data>
@@ -28,7 +28,7 @@
 				<DataPoint name="installationLocation" readable="true" writable="true">
 					<Doc>This property indicates the installation location</Doc>
 					<DataType>
-						<SimpleType type="string" />
+						<Simple type="string" />
 					</DataType>
 				</DataPoint>
 			</Data>
@@ -46,7 +46,7 @@
 				<DataPoint name="measuredInstantaneousPowerConsumption" readable="true" writable="false">
 					<Doc>This property indicates the instantaneous power consumption of the device in watts.</Doc>
 					<DataType unitOfMeasure="watts">
-						<SimpleType type="integer" />
+						<Simple type="integer" />
 					</DataType>
 				</DataPoint>
 			</Data>
@@ -57,7 +57,7 @@
 				<DataPoint name="measuredTemperatureValue" readable="true" writable="false">
 					<Doc>This property indicates the measured temperature value in units of 0.1C.</Doc>
 					<DataType unitOfMeasure="celsius">
-						<SimpleType type="integer" />
+						<Simple type="integer" />
 					</DataType>
 				</DataPoint>
 			</Data>
@@ -74,10 +74,10 @@
 
 			<Properties>
 				<Property name="Name" value="washing machine">
-					<SimpleType type="string" />
+					<Simple type="string" />
 				</Property>
 				<Property name="Vendor" value="ACME">
-					<SimpleType type="string" />
+					<Simple type="string" />
 				</Property>
 			</Properties>
 
@@ -122,25 +122,25 @@
 						<DataPoint name="door_CoverOpen_CloseStatus" readable="true" writable="false">
 							<Doc>This property indicates whether the door/cover is open or closed.</Doc>
 							<DataType>
-								<SimpleType type="boolean" />
+								<Simple type="boolean" />
 							</DataType>
 						</DataPoint>
 						<DataPoint name="washingMachineSetting" readable="true" writable="true">
 							<Doc>Washing machine setting</Doc>
 							<DataType>
-								<SimpleType type="string" />
+								<Simple type="string" />
 							</DataType>
 						</DataPoint>
 						<DataPoint name="currentStageOfWashingCycle" readable="true" writable="false">
 							<Doc>This property indicates the current stage of the washing cycle.</Doc>
 							<DataType>
-								<SimpleType type="string" />
+								<Simple type="string" />
 							</DataType>
 						</DataPoint>
 						<DataPoint name="timeRemainingToCompleteWashingCycle" readable="true" writable="false">
 							<Doc>This property indicates the time remaining to complete the current washing cycle in the HH:MM:SS format.</Doc>
 							<DataType>
-								<SimpleType type="time" />
+								<Simple type="time" />
 							</DataType>
 						</DataPoint>
 
@@ -152,19 +152,19 @@
 						<DataPoint name="onTimerReservationSetting" readable="true" writable="true">
 							<Doc>Reservation ON/OFF</Doc>
 							<DataType>
-								<SimpleType type="boolean" />
+								<Simple type="boolean" />
 							</DataType>
 						</DataPoint>
 						<DataPoint name="onTimerSetting" readable="true" writable="true">
 							<Doc>Timer value (HH:MM)</Doc>
 							<DataType>
-								<SimpleType type="time" />
+								<Simple type="time" />
 							</DataType>
 						</DataPoint>
 						<DataPoint name="relativeTimeBasedOnTimerSetting" readable="true" writable="true">
 							<Doc>Timer value (HH:MM)</Doc>
 							<DataType>
-								<SimpleType type="time" />
+								<Simple type="time" />
 							</DataType>
 						</DataPoint>
 					</Data>
diff --git a/SDT/schema4.0/test/SimpleExample.xml b/SDT/schema4.0/test/SimpleExample.xml
index d9d097068c985de8ab86096407aeddf619a6e843..b959d2b5105333d88dbc540fc36d2d7abfe63b1f 100644
--- a/SDT/schema4.0/test/SimpleExample.xml
+++ b/SDT/schema4.0/test/SimpleExample.xml
@@ -9,7 +9,7 @@
 						<DataPoint name="status" readable="true" writable="true">
 							<Doc>This property indicates the ON/OFF status.</Doc>
 							<DataType>
-								<SimpleType type="boolean" />
+								<Simple type="boolean" />
 							</DataType>
 						</DataPoint>
 					</Data>
diff --git a/SDT/schema4.0/test/arg-test.xml b/SDT/schema4.0/test/arg-test.xml
index 5d6261dd6b22120f7cdea8134d287abfe552383a..4828438f3079efbf7e6b5f9637c5816e7de82216 100644
--- a/SDT/schema4.0/test/arg-test.xml
+++ b/SDT/schema4.0/test/arg-test.xml
@@ -10,12 +10,12 @@
 					<Args>
 						<Arg name="argMandatory">
 							<DataType>
-								<SimpleType type="boolean" />
+								<Simple type="boolean" />
 							</DataType>
 						</Arg>
 						<Arg name="argOptional" optional="true">
 							<DataType>
-								<SimpleType type="boolean" />
+								<Simple type="boolean" />
 							</DataType>
 						</Arg>
 					</Args>
@@ -24,12 +24,12 @@
 					<Args>
 						<Arg name="arg1" default="true">
 							<DataType>
-								<SimpleType type="boolean" />
+								<Simple type="boolean" />
 							</DataType>
 						</Arg>
 						<Arg name="arg2" default="foo">
 							<DataType>
-								<SimpleType type="string" />
+								<Simple type="string" />
 							</DataType>
 						</Arg>
 					</Args>
diff --git a/SDT/schema4.0/test/dal-core.xml b/SDT/schema4.0/test/dal-core.xml
index e270b6f849c637866ba9d35a11f9c48da9de0fd1..34a6bc9f12d624bc1c93a0b66a301d76f9a8f2ac 100644
--- a/SDT/schema4.0/test/dal-core.xml
+++ b/SDT/schema4.0/test/dal-core.xml
@@ -16,7 +16,7 @@
 				<Action name="get">
 					<Doc>Obtain the current associated state.</Doc>
 					<DataType>
-						<SimpleType type="boolean" />
+						<Simple type="boolean" />
 					</DataType>
 				</Action>
 				<Action name="setTarget">
@@ -25,7 +25,7 @@
 						<Arg name="value">
 							<Doc>The desired value of the associated state.</Doc>
 							<DataType>
-								<SimpleType type="boolean" />
+								<Simple type="boolean" />
 							</DataType>
 						</Arg>
 					</Args>
diff --git a/SDT/schema4.0/test/dal-eg.xml b/SDT/schema4.0/test/dal-eg.xml
index a29d7e0a63af3177d38e9bd7de5a68338c402ccd..e197de91802c145be93aa6f794df237b38a27b30 100644
--- a/SDT/schema4.0/test/dal-eg.xml
+++ b/SDT/schema4.0/test/dal-eg.xml
@@ -9,12 +9,12 @@
 			<Properties>
 				<Property name="Name">
 					<Doc>Original value: PowerSwitch</Doc>
-					<SimpleType type="string"/>
+					<Simple type="string"/>
 				</Property>
 				<!-- The Vendor field should probably be part of the domain -->
 				<Property name="Vendor">
 					<Doc>Original value: Telekom Innovation Laboratories</Doc>
-					<SimpleType type="string"/>
+					<Simple type="string"/>
 				</Property>
 			</Properties>
 			<ModuleClasses>
@@ -30,7 +30,7 @@
 						<Action name="state">
 							<Doc>Query the state of the switch. Returns the string &quot;<tt>on</tt>&quot; or &quot;<tt>off</tt>&quot;.</Doc>
 							<DataType>
-								<SimpleType type="string"/>
+								<Simple type="string"/>
 							</DataType>
 						</Action>
 					</Actions>
@@ -40,7 +40,7 @@
 							<Data>
 								<DataPoint name="state" writable="false">
 									<DataType>
-										<SimpleType type="boolean"/>
+										<Simple type="boolean"/>
 									</DataType>
 								</DataPoint>
 							</Data>
diff --git a/SDT/schema4.0/test/datapoint-test.xml b/SDT/schema4.0/test/datapoint-test.xml
index 6100a5dec8126e2735960cf6fde3f1c06fce6cef..e7005b011d89f2053d08addf0165270818509de5 100644
--- a/SDT/schema4.0/test/datapoint-test.xml
+++ b/SDT/schema4.0/test/datapoint-test.xml
@@ -7,7 +7,7 @@
 			<Data>
 				<DataPoint name="TestDataPoint" optional="true" default="foo">
 					<DataType>
-						<SimpleType type="string" />
+						<Simple type="string" />
 					</DataType>
 				</DataPoint>
 			</Data>
diff --git a/SDT/schema4.0/test/datatypes-test.xml b/SDT/schema4.0/test/datatypes-test.xml
index 80f9071e69a4c28a0d543c9f1718e0310f183c09..102322080f0ea13d7b54565d70cd2945aee2d0dc 100644
--- a/SDT/schema4.0/test/datatypes-test.xml
+++ b/SDT/schema4.0/test/datatypes-test.xml
@@ -4,7 +4,7 @@
 <Domain id="datatypes-test" xmlns="http://www.onem2m.org/xml/sdt/4.0" xmlns:xi="http://www.w3.org/2001/XInclude">
 	<DataTypes>
 		<DataType name="temperatureType" unitOfMeasure="C">
-			<SimpleType type="float"/>
+			<Simple type="float"/>
 		</DataType>
 		<DataType name="anEnumType">
 			<Enum>
diff --git a/SDT/schema4.0/test/deviceClass-test.xml b/SDT/schema4.0/test/deviceClass-test.xml
index 1500f3dfe006ca081f36fef665a790ef5e96a5c0..8b96b74fa635d1380d3742a19d8af463c596658f 100644
--- a/SDT/schema4.0/test/deviceClass-test.xml
+++ b/SDT/schema4.0/test/deviceClass-test.xml
@@ -8,7 +8,7 @@
 			<Doc>This is a test device.</Doc>
 			<Properties>
 				<Property name="aProperty">
-					<SimpleType type="string"></SimpleType>
+					<Simple type="string" />
 				</Property>
 			</Properties>
 			<ModuleClasses>
diff --git a/SDT/schema4.0/test/deviceModbusTemperature.xml b/SDT/schema4.0/test/deviceModbusTemperature.xml
index 1ad3801748e038aa29bea14ce1ee076fbde2a0b3..2fdc64c2634fe60fe18d6193a779f3578479b898 100644
--- a/SDT/schema4.0/test/deviceModbusTemperature.xml
+++ b/SDT/schema4.0/test/deviceModbusTemperature.xml
@@ -7,37 +7,37 @@
 				<DataPoint name="currentTemperature" readable="true" writable="false" eventable="true" optional="false">
 					<Doc>The current temperature.</Doc>
 					<DataType>
-						<SimpleType type="float" />
+						<Simple type="float" />
 					</DataType>
 				</DataPoint>
 				<DataPoint name="targetTemperature" readable="true" writable="true" eventable="true" optional="true">
 					<Doc>The desired temperature to reach.</Doc>
 					<DataType>
-						<SimpleType type="float" />
+						<Simple type="float" />
 					</DataType>
 				</DataPoint>
 				<DataPoint name="unit" readable="true" writable="false" eventable="true" optional="true">
 					<Doc>The unit of measure for the temperature values. The default is Celsius (C).</Doc>
 					<DataType>
-						<SimpleType type="string" />
+						<Simple type="string" />
 					</DataType>
 				</DataPoint>
 				<DataPoint name="minValue" readable="true" writable="false" eventable="true" optional="true">
 					<Doc>Minimum value of "targetTemperature".</Doc>
 					<DataType>
-						<SimpleType type="float" />
+						<Simple type="float" />
 					</DataType>
 				</DataPoint>
 				<DataPoint name="maxValue" readable="true" writable="false" eventable="true" optional="true">
 					<Doc>Maximum value of "targetTemperature".</Doc>
 					<DataType>
-						<SimpleType type="float" />
+						<Simple type="float" />
 					</DataType>
 				</DataPoint>
 				<DataPoint name="stepValue" readable="true" writable="false" eventable="true" optional="true">
 					<Doc>Step value allowed for "targetTemperature".</Doc>
 					<DataType>
-						<SimpleType type="float" />
+						<Simple type="float" />
 					</DataType>
 				</DataPoint>
 			</Data>
@@ -49,16 +49,16 @@
 			<Doc>This is a test device.</Doc>
 			<Properties>
 				<Property name="address">
-					<SimpleType type="string" />
+					<Simple type="string" />
 				</Property>
 				<Property name="functionCode">
-					<SimpleType type="string" />
+					<Simple type="string" />
 				</Property>
 				<Property name="registers">
-					<SimpleType type="string" />
+					<Simple type="string" />
 				</Property>
 				<Property name="slaveID">
-					<SimpleType type="string" />
+					<Simple type="string" />
 				</Property>
 			</Properties>
 			<ModuleClasses>
diff --git a/SDT/schema4.0/test/example1.SDT.xml b/SDT/schema4.0/test/example1.SDT.xml
index f263033e397e6d22b3c5bec6784ef2ee7137dafe..0837430101de2db65369126e62e6f34ac9ab8b70 100644
--- a/SDT/schema4.0/test/example1.SDT.xml
+++ b/SDT/schema4.0/test/example1.SDT.xml
@@ -12,7 +12,7 @@
 				<DataPoint name="operationStatus" writable="true">
 					<Doc>This property sets the ON/OFF status.</Doc>
 						<DataType>
-							<SimpleType type="boolean"/> 
+							<Simple type="boolean"/> 
 						</DataType>
 				</DataPoint>
 			</Data>
@@ -28,7 +28,7 @@
 				<DataPoint name="installationLocation" writable="true">
 					<Doc>This property indicates the installation location</Doc>
 					<DataType>
-						<SimpleType type="string"/>
+						<Simple type="string"/>
 					</DataType>
 				</DataPoint>
 			</Data>
@@ -42,7 +42,7 @@
 				<DataPoint name="measuredCumulativePowerConsumption" writable="false">
 					<Doc>This indicates cumulative power consumption of the device in increments of 0.001kWh.</Doc>
 					<DataType unitOfMeasure="watt">
-						<SimpleType type="integer"/>
+						<Simple type="integer"/>
 					</DataType>
 				</DataPoint>
 			</Data>
@@ -53,7 +53,7 @@
 				<DataPoint name="onTimer" writable="true">
 					<Doc>Timer value (HH:MM)</Doc>
 					<DataType>
-						<SimpleType type="time"/>
+						<Simple type="time"/>
 					</DataType>
 				</DataPoint>
 			</Data>
@@ -64,7 +64,7 @@
 				<DataPoint name="statusDoor" writable="false">
 					<Doc>This reads the open=true or closed=false status of a door </Doc>
 					<DataType>
-						<SimpleType type="boolean"/>
+						<Simple type="boolean"/>
 					</DataType>
 				</DataPoint>
 			</Data>
diff --git a/SDT/schema4.0/test/extends-test.xml b/SDT/schema4.0/test/extends-test.xml
index bc39389aba49432c6e5d63f17ef6e1654d5c5ca8..c14eead86b99b66b77fa66bafd779d8bac135fef 100644
--- a/SDT/schema4.0/test/extends-test.xml
+++ b/SDT/schema4.0/test/extends-test.xml
@@ -7,12 +7,12 @@
 			<Data>
 				<DataPoint name="TestExtendsDataPoint1" writable="true">
 					<DataType>
-						<SimpleType type="integer" />
+						<Simple type="integer" />
 					</DataType>
 				</DataPoint>
 				<DataPoint name="TestExtendsDataPoint2" writable="true">
 					<DataType>
-						<SimpleType type="integer" />
+						<Simple type="integer" />
 					</DataType>
 				</DataPoint>
 			</Data>
@@ -25,7 +25,7 @@
 			<Data>
 				<DataPoint name="TestExtendsDataPoint3" writable="true">
 					<DataType>
-						<SimpleType type="integer" />
+						<Simple type="integer" />
 					</DataType>
 				</DataPoint>
 			</Data>
diff --git a/SDT/schema4.0/test/mseeb.xml b/SDT/schema4.0/test/mseeb.xml
index 7ce9b37cdfacd6e38b1cec379328c3dbc426ddb7..86fdbe90842fe650543af451b54122fc912d8634 100644
--- a/SDT/schema4.0/test/mseeb.xml
+++ b/SDT/schema4.0/test/mseeb.xml
@@ -82,7 +82,7 @@
                         Obtain the current associated state.
                     </Doc>
                     <DataType>
-                        <SimpleType type="boolean" />
+                        <Simple type="boolean" />
                     </DataType>
                 </Action>
                 <Action name="setTarget">
@@ -95,7 +95,7 @@
                             The desired value of the associated state.
                             </Doc>
                             <DataType>
-                                <SimpleType type="boolean" />
+                                <Simple type="boolean" />
                             </DataType>
                         </Arg>
                     </Args>
@@ -106,7 +106,7 @@
                     <Data>
                         <DataPoint name="state" readable="true">
                             <DataType>
-                        		<SimpleType type="boolean" />
+                        		<Simple type="boolean" />
                             </DataType>
                         </DataPoint>
                     </Data>
@@ -128,23 +128,23 @@
             <Properties>
                 <Property name="Name">
                     <Doc>Original value: Multi Socket Electrical-Extension-Block</Doc>
-                    <SimpleType type="string" />
+                    <Simple type="string" />
                 </Property>
                 <Property name="Vendor">
                     <Doc>Original value: HGI</Doc>
-                    <SimpleType type="string" />
+                    <Simple type="string" />
                 </Property>
                 <Property name="FirmwareVersion">
                   <Doc>Original value: 1.0</Doc>
-                  <SimpleType type="string" />
+                  <Simple type="string" />
                 </Property>
                 <Property name="VendorURL">
                   <Doc>Original value: http://www.onem2m.org</Doc>
-                  <SimpleType type="uri" />
+                  <Simple type="uri" />
                 </Property>
                 <Property name="SerialNumber">
                   <Doc>Original value: 1234.5</Doc>
-                  <SimpleType type="string" />
+                  <Simple type="string" />
                 </Property>
             </Properties>
 
@@ -163,7 +163,7 @@
                     <Properties>
                         <Property name="version" value="1.0.0">
                             <Doc>Version for this ModuleClass</Doc>
-                            <SimpleType type="string" />
+                            <Simple type="string" />
                         </Property>
                     </Properties>
                 </ModuleClass>
@@ -177,7 +177,7 @@
                         				<Array>
                                            <DataType>
                                                 <Doc>This is an example simple data type with a minimum-value constraint.</Doc>
-                            					<SimpleType type="float" />
+                            					<Simple type="float" />
                                                 <Constraints>
                                                     <Constraint name="minValue" type="float" value="0.0">
                                                         <Doc>The value must be equal or greater 0.0</Doc>
@@ -192,7 +192,7 @@
                                     <DataType name="timeFrame">
                         				<Array>
                                             <DataType>
-                            					<SimpleType type="datetime" />
+                            					<Simple type="datetime" />
                                             </DataType>
                 				        </Array>
                                     </DataType>
@@ -208,7 +208,7 @@
                             <DataType name="names">
                                 <Array>
                                     <DataType>
-                                        <SimpleType type="string" />
+                                        <Simple type="string" />
                                     </DataType>
                                 </Array>
                             </DataType>
@@ -222,7 +222,7 @@
                                 This datapoint represents the firmware version of the extension block.
                             </Doc>
                             <DataType>
-                                <SimpleType type="string" />
+                                <Simple type="string" />
                             </DataType>
                         </DataPoint>
                         
@@ -235,7 +235,7 @@
                             <DataType>
                                 <Array>
                                     <DataType>
-                                        <SimpleType type="string" />
+                                        <Simple type="string" />
                                     </DataType>
                                 </Array>
                             </DataType>
@@ -257,10 +257,10 @@
                     </Doc>
                     <Properties>
                         <Property name="Name" value="PowerSwitch 1">
-                            <SimpleType type="string" />
+                            <Simple type="string" />
                         </Property>
                         <Property name="Vendor" value="HGI">
-                            <SimpleType type="string" />
+                            <Simple type="string" />
                         </Property>
                     </Properties>
                     <ModuleClasses>
@@ -278,16 +278,16 @@
                     </Doc>
                     <Properties>
                         <Property name="Name" value="PowerSwitch 2">
-                            <SimpleType type="string" />
+                            <Simple type="string" />
                         </Property>
                         <Property name="Vendor" value="HGI">
-                            <SimpleType type="string" />
+                            <Simple type="string" />
                         </Property>
                         <Property name="VendorURL" value="http://www.onem2m.org">
-                            <SimpleType type="uri" />
+                            <Simple type="uri" />
                         </Property>
                         <Property name="maximumAltitude" value="2800">
-                            <SimpleType type="integer" />
+                            <Simple type="integer" />
                         </Property>
                     </Properties>
                     <ModuleClasses>
diff --git a/SDT/schema4.0/test/productClass-test.xml b/SDT/schema4.0/test/productClass-test.xml
index c83ba9312bec444f08b569eab476ba7b7e6b23f3..361ed494eacd2a987351b60a3577359a776d5b2e 100644
--- a/SDT/schema4.0/test/productClass-test.xml
+++ b/SDT/schema4.0/test/productClass-test.xml
@@ -5,7 +5,7 @@
 			<Doc>This is a test product</Doc>
 			<Properties>
 				<Property name="aProperty">
-					<SimpleType type="string"></SimpleType>
+					<Simple type="string" />
 				</Property>
 			</Properties>
 			<ModuleClasses>
diff --git a/SDT/schema4.0/test/semanticURI-test.xml b/SDT/schema4.0/test/semanticURI-test.xml
index 9a4a3518ebe5a8e0c7d2989e01622f27d72f7a9a..e6e6a08220f1858ee95a4414b425276af2739373 100644
--- a/SDT/schema4.0/test/semanticURI-test.xml
+++ b/SDT/schema4.0/test/semanticURI-test.xml
@@ -4,7 +4,7 @@
 <Domain id="semanticURI-test" xmlns="http://www.onem2m.org/xml/sdt/4.0" xmlns:xi="http://www.w3.org/2001/XInclude" semanticURI="http://example.com/semanticURI-test.rdf">
 	<DataTypes>
 		<DataType name="temperatureType" unitOfMeasure="C" semanticURI="http://example.com/temperatureType.rdf">
-			<SimpleType type="float"/>
+			<Simple type="float"/>
 		</DataType>
 		<DataType name="anEnumType" semanticURI="http://example.com/anEnumType.rdf">
 			<Enum>
diff --git a/SDT/schema4.0/test/subdevices-test.xml b/SDT/schema4.0/test/subdevices-test.xml
index 1cf88dcae083a1108b56dadd67138f796384dce1..1ce6f518ccc894293518ca8e1268d41433b33b94 100644
--- a/SDT/schema4.0/test/subdevices-test.xml
+++ b/SDT/schema4.0/test/subdevices-test.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- Test the data types references -->
+<!-- Test the sub-device references -->
 
 <Domain id="subdevices-test" xmlns="http://www.onem2m.org/xml/sdt/4.0" xmlns:xi="http://www.w3.org/2001/XInclude">
 	<SubDevices>
@@ -9,7 +9,7 @@
 					<Data>
 						<DataPoint name="aDataPoint">
 							<DataType>
-								<SimpleType type="boolean" />
+								<Simple type="boolean" />
 							</DataType>
 						</DataPoint>
 					</Data>
diff --git a/SDT/schema4.0/test/void-test.xml b/SDT/schema4.0/test/void-test.xml
index 32b836bf511f6508e17abbae2d09b4029a2b1fca..6f115a89990f36917327c2657e90ad0cfa87b4e7 100644
--- a/SDT/schema4.0/test/void-test.xml
+++ b/SDT/schema4.0/test/void-test.xml
@@ -7,14 +7,14 @@
 			<Actions>
 				<Action name="TestVoidAction">
 					<DataType>
-						<SimpleType type="void"/>
+						<Simple type="void"/>
 					</DataType>
 				</Action>
 			</Actions>
 			<Data>
 				<DataPoint name="TestVoidDataPoint" writable="true">
 					<DataType>
-						<SimpleType type="void"/>
+						<Simple type="void"/>
 					</DataType>
 				</DataPoint>
 			</Data>