diff --git a/SDT/schema4.0/etc/domain.rnc b/SDT/schema4.0/etc/domain.rnc
index 9eeaa53e98f610d97936947f051f6a55fc7f9ee9..722416663657c1fe9c4f4b7d4cdb8804ebc3f6ec 100644
--- a/SDT/schema4.0/etc/domain.rnc
+++ b/SDT/schema4.0/etc/domain.rnc
@@ -11,7 +11,7 @@ start = Domain
 Domain =
   element Domain {
     attribute xml:base { xsd:anyURI }?,
-    attribute id { xsd:ID },
+    attribute id { xsd:Name },
     DocDef,
     element Imports { Domain+ }?,
     element DataTypes { DataTypeDef+ }?,
@@ -159,7 +159,7 @@ ExtendsDef =
   # TODO: singular
   element extends {
     #  TODO: Uppercase , singular
-    attribute domain { xsd:IDREF },
+    attribute domain { xsd:Name },
     attribute class { text },
     element excludes {
       #  TODO: Uppercase + "...s" -> Excludes
diff --git a/SDT/schema4.0/src/domain.rng b/SDT/schema4.0/src/domain.rng
index 7527cabfb941e1806f9c65fc9468f834d5556077..715c324930a3f91c4818f336775fbae9e46a554a 100644
--- a/SDT/schema4.0/src/domain.rng
+++ b/SDT/schema4.0/src/domain.rng
@@ -26,7 +26,7 @@
 				</attribute>
 			</optional>
 			<attribute name="id">
-				<data type="ID"/>
+				<data type="Name"/>
 			</attribute>
 			<ref name="DocDef"/>
 			<optional>
@@ -407,7 +407,7 @@
 		<optional>
 			<element name="extends"> <!-- TODO: Uppercase , singular-->
 				<attribute name="domain">
-					<data type="IDREF"/>
+					<data type="Name"/>
 				</attribute>
 				<attribute name="class"/>
 				<optional>
diff --git a/SDT/schema4.0/src/domain.xsd b/SDT/schema4.0/src/domain.xsd
index 5375d8aa487f5827695cfa6963545bc69bb79bb2..3b8bbeb5190865d22442762b053934d3e2d654a2 100644
--- a/SDT/schema4.0/src/domain.xsd
+++ b/SDT/schema4.0/src/domain.xsd
@@ -26,7 +26,7 @@
             <xs:element minOccurs="0" ref="DeviceClasses"/>
           </xs:sequence>
           <xs:attribute ref="xml:base"/>
-          <xs:attribute name="id" use="required" type="xs:ID"/>
+          <xs:attribute name="id" use="required" type="xs:Name"/>
         </xs:extension>
       </xs:complexContent>
     </xs:complexType>
@@ -360,7 +360,7 @@
       <xs:sequence>
         <xs:element minOccurs="0" ref="excludes"/>
       </xs:sequence>
-      <xs:attribute name="domain" use="required" type="xs:IDREF"/>
+      <xs:attribute name="domain" use="required" type="xs:Name"/>
       <xs:attribute name="class" use="required"/>
     </xs:complexType>
   </xs:element>