diff --git a/audio/2.0/config/audio_policy_configuration.xsd b/audio/2.0/config/audio_policy_configuration.xsd
index eb59152..8c05763 100644
--- a/audio/2.0/config/audio_policy_configuration.xsd
+++ b/audio/2.0/config/audio_policy_configuration.xsd
@@ -73,14 +73,28 @@
     <!-- Enum values of IDevicesFactory::Device
          TODO: generate from hidl to avoid manual sync. -->
     <xs:simpleType name="halName">
-        <xs:restriction base="xs:string">
-            <xs:enumeration value="primary"/>
-            <xs:enumeration value="a2dp"/>
-            <xs:enumeration value="usb"/>
-            <xs:enumeration value="r_submix"/>
-            <xs:enumeration value="codec_offload"/>
-            <xs:enumeration value="stub"/>
-        </xs:restriction>
+        <xs:union>
+            <xs:simpleType>
+                <xs:restriction base="xs:string">
+                    <xs:enumeration value="primary"/>
+                    <xs:enumeration value="a2dp"/>
+                    <xs:enumeration value="usb"/>
+                    <xs:enumeration value="r_submix"/>
+                    <xs:enumeration value="codec_offload"/>
+                    <xs:enumeration value="stub"/>
+                </xs:restriction>
+            </xs:simpleType>
+            <xs:simpleType>
+                <!-- Vendor eXtension names must be in the vx namespace.
+                     Vendor are encouraged to namespace their module names.
+                     Example for an hypothetical Google virtual reality HAL:
+                        <module name="vx_google_vr" halVersion="3.0">
+                -->
+                <xs:restriction base="xs:string">
+                    <xs:pattern value="vx_[_a-zA-Z0-9]+"/>
+                </xs:restriction>
+            </xs:simpleType>
+        </xs:union>
     </xs:simpleType>
     <xs:complexType name="modules">
         <xs:annotation>