diff --git a/schema.xsd b/schema.xsd
index 16ca5c3..ca8f6b4 100644
--- a/schema.xsd
+++ b/schema.xsd
@@ -6,7 +6,9 @@
     <xsd:import namespace="http://www.w3.org/XML/1998/namespace"/>
 
     <xsd:element name="library">
-        <xsd:annotation><xsd:documentation>Root element for library.xml files</xsd:documentation></xsd:annotation>
+        <xsd:annotation>
+            <xsd:documentation>Root element for library.xml files</xsd:documentation>
+        </xsd:annotation>
         <xsd:complexType>
             <xsd:sequence>
                 <xsd:element type="ExternalLib" name="external-lib" minOccurs="0" maxOccurs="unbounded"/>
@@ -20,7 +22,9 @@
     </xsd:complexType>
 
     <xsd:element name="family">
-        <xsd:annotation><xsd:documentation>Root element for family definition files</xsd:documentation></xsd:annotation>
+        <xsd:annotation>
+            <xsd:documentation>Root element for family definition files</xsd:documentation>
+        </xsd:annotation>
         <xsd:complexType>
             <xsd:sequence>
                 <xsd:element type="xsd:string" name="description"/>
@@ -84,7 +88,7 @@
     <xsd:complexType name="Enum">
         <xsd:sequence>
             <xsd:element type="xsd:string" name="description" minOccurs="0"/>
-            <xsd:element type="ItemList" name="item-list" minOccurs="0"/>
+            <xsd:element type="EnumItemList" name="item-list" minOccurs="0"/>
         </xsd:sequence>
         <xsd:attribute type="xsd:string" name="name" use="required"/>
         <xsd:attribute type="xsd:boolean" name="noCount"/>
@@ -132,22 +136,22 @@
         <xsd:attribute type="xsd:string" name="name" use="required"/>
     </xsd:complexType>
 
-    <xsd:complexType name="ItemList">
+    <xsd:complexType name="EnumItemList">
         <xsd:sequence>
-            <xsd:element type="Item" name="item" minOccurs="1" maxOccurs="unbounded"/>
+            <xsd:element type="EnumItem" name="item" minOccurs="1" maxOccurs="unbounded"/>
         </xsd:sequence>
     </xsd:complexType>
 
     <xsd:complexType name="BitfieldItemList">
         <xsd:sequence>
             <xsd:choice minOccurs="1" maxOccurs="unbounded">
-                <xsd:element type="Item" name="item" minOccurs="0"/>
+                <xsd:element type="BitfieldItem" name="item" minOccurs="0"/>
                 <xsd:element type="RefWithSize" name="enum-ref" minOccurs="0"/>
             </xsd:choice>
         </xsd:sequence>
     </xsd:complexType>
 
-    <xsd:complexType name="Item">
+    <xsd:complexType name="BaseItem">
         <xsd:sequence>
             <xsd:element type="xsd:string" name="description" minOccurs="0"/>
             <xsd:element type="xsd:string" name="label" minOccurs="0">
@@ -158,11 +162,43 @@
                 </xsd:annotation>
             </xsd:element>
         </xsd:sequence>
-        <xsd:attribute type="xsd:string" name="name"/>
+        <xsd:attribute type="xsd:string" name="name" use="required"/>
         <xsd:attribute type="xsd:int" name="value"/>
-        <xsd:attribute type="xsd:int" name="size"/>
-        <xsd:attribute type="xsd:string" name="type"/>
-        <xsd:attribute type="xsd:string" name="deviceType"/>
+    </xsd:complexType>
+
+    <xsd:complexType name="BitfieldItem">
+        <xsd:complexContent>
+            <xsd:extension base="BaseItem">
+                <xsd:attribute type="xsd:int" name="size"/>
+            </xsd:extension>
+        </xsd:complexContent>
+    </xsd:complexType>
+
+    <xsd:complexType name="AssociatedEnum">
+        <xsd:complexContent>
+            <xsd:extension base="UnnamedRef">
+                <xsd:attribute type="xsd:string" name="field" use="required"/>
+            </xsd:extension>
+        </xsd:complexContent>
+    </xsd:complexType>
+
+    <xsd:complexType name="EnumItem">
+        <xsd:complexContent>
+            <xsd:extension base="BaseItem">
+                <xsd:sequence>
+                    <xsd:element type="AssociatedEnum" name="associatedEnum" minOccurs="0" maxOccurs="unbounded">
+                        <xsd:annotation>
+                            <xsd:documentation>When this enum value is used, the referenced field will be an enum of the given enum type.</xsd:documentation>
+                        </xsd:annotation>
+                    </xsd:element>
+                </xsd:sequence>
+                <xsd:attribute type="xsd:string" name="deviceType">
+                    <xsd:annotation>
+                        <xsd:documentation>Deprecated, use associatedEnum instead.</xsd:documentation>
+                    </xsd:annotation>
+                </xsd:attribute>
+            </xsd:extension>
+        </xsd:complexContent>
     </xsd:complexType>
 
     <xsd:complexType name="BaseCollection">