diff --git a/build.xml b/build.xml
index 748dcd79..a6d4c3b4 100644
--- a/build.xml
+++ b/build.xml
@@ -492,8 +492,16 @@
 		
 		<!-- [31] -->
 		<echo>   Fallback aggregate...</echo>
-		<XALAN.xmldir x="uk_master_back.xsl" i="${uk.master.file}"
-			o="${md.back.unsigned}" />
+        <XALAN
+            x="${build.dir}/uk_master_back.xsl"
+            i="${xml.dir}/${uk.master.file}"
+            o="${temp.xml}"/>
+        <echo>      normalising namespaces...</echo>
+        <XALAN
+            x="${build.dir}/ns_norm_uk.xsl"
+            i="${temp.xml}"
+            o="${xml.dir}/${md.back.unsigned}" />
+        <MDNORM i="${xml.dir}/${md.back.unsigned}"/>
         <CHECK.publishable i="${xml.dir}/${md.back.unsigned}"/>
 		
         <echo>Generated UK unsigned metadata.</echo>
@@ -864,7 +872,7 @@
 
 		<echo>Signing UK fallback metadata.</echo>
 		<!-- [32] -->
-		<MDT.SIGN.uk i="${md.back.unsigned}" o="${md.back.signed}"/>
+		<SIGN.uk i="${md.back.unsigned}" o="${md.back.signed}"/>
 		
 		<echo>Generated signed UK metadata.</echo>
 	</target>
diff --git a/build/uk_master_back.xsl b/build/uk_master_back.xsl
index 13f39999..67a68beb 100644
--- a/build/uk_master_back.xsl
+++ b/build/uk_master_back.xsl
@@ -15,7 +15,7 @@
 -->
 <xsl:stylesheet version="1.0"
 	xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata"
-	xmlns:mdui="urn:oasis:names:tc:SAML:metadata:ui"
+	xmlns:shibmd="urn:mace:shibboleth:metadata:1.0"
 	xmlns:ukfedlabel="http://ukfederation.org.uk/2006/11/label"
 	xmlns:wayf="http://sdss.ac.uk/2006/06/WAYF"
 	
@@ -27,7 +27,7 @@
 	xmlns="urn:oasis:names:tc:SAML:2.0:metadata"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
-	exclude-result-prefixes="mdui wayf">
+	exclude-result-prefixes="md">
 
 	<!--Force UTF-8 encoding for the output.-->
 	<xsl:output omit-xml-declaration="no" method="xml" encoding="UTF-8" indent="yes"/>
@@ -42,7 +42,21 @@
 	
 	<xsl:variable name="now" select="date:date-time()"/>
 	<xsl:variable name="validUntil" select="mdxDates:dateAdd($now, $validityDays)"/>
-	
+	
+	<!--
+		documentID
+		
+		This value is generated from a normalised version of the aggregation instant,
+		transformed so that it can be used as an XML ID value.
+		
+		Strict conformance to the SAML 2.0 metadata specification (section 3.1.2) requires
+		that the signature explicitly references an identifier attribute in the element
+		being signed, in this case the document element.
+	-->
+	<xsl:variable name="normalisedNow" select="mdxDates:dateAdd($now, 0)"/>
+	<xsl:variable name="documentID"
+		select="concat('uk', translate($normalisedNow, ':-', ''))"/>
+
 	<!--
 		Document root.
 	-->
@@ -55,20 +69,24 @@
 		Document element.
 	-->
 	<xsl:template match="/md:EntitiesDescriptor">
-		<xsl:copy>
+		<EntitiesDescriptor>
 			<xsl:attribute name="validUntil">
 				<xsl:value-of select="$validUntil"/>
+			</xsl:attribute>
+			<xsl:attribute name="ID">
+				<xsl:value-of select="$documentID"/>
 			</xsl:attribute>
 			<xsl:apply-templates select="@*"/>
 			<xsl:call-template name="document.comment"/>
 			<xsl:apply-templates select="node()"/>
-		</xsl:copy>
+		</EntitiesDescriptor>
 	</xsl:template>
 
 	<!--
 		Comment to be added to the top of the document, and just inside the document element.
 	-->
-	<xsl:template name="document.comment">
+	<xsl:template name="document.comment">
+		<xsl:text>&#10;</xsl:text>
 		<xsl:comment>
 			<xsl:text>&#10;&#9;U K   F E D E R A T I O N   M E T A D A T A&#10;</xsl:text>
 			<xsl:text>&#10;</xsl:text>
@@ -84,6 +102,7 @@
 			<xsl:value-of select="$validUntil"/>
 			<xsl:text>&#10;</xsl:text>
 		</xsl:comment>
+		<xsl:text>&#10;</xsl:text>
 	</xsl:template>
 	
 	<!--
@@ -133,9 +152,8 @@
 	<!--
 		Pass through certain ukfedlabel namespace elements.
 	-->
-	<xsl:template match="ukfedlabel:UKFederationMember |
-		ukfedlabel:SDSSPolicy |
-		ukfedlabel:AccountableUsers">
+	
+	<xsl:template match="ukfedlabel:UKFederationMember | ukfedlabel:AccountableUsers">
 		<xsl:copy>
 			<xsl:apply-templates select="node()|@*"/>
 		</xsl:copy>
@@ -147,13 +165,6 @@
 	<xsl:template match="ukfedlabel:*">
 		<!-- do nothing -->
 	</xsl:template>
-	
-	<!--
-		Strip all discovery user interface elements entirely.
-	-->
-	<xsl:template match="mdui:*">
-		<!-- do nothing -->
-	</xsl:template>
 	
 	<!--
 		Remove administrative contacts.
@@ -161,9 +172,25 @@
 	<xsl:template match="md:ContactPerson[@contactType='administrative']">
 		<!-- do nothing -->
 	</xsl:template>
-	
-	<!--By default, copy text blocks, comments and attributes unchanged.-->
-	<xsl:template match="text()|comment()|@*">
+	
+	<!--
+		Retain only certain comments.
+	-->
+	
+	<xsl:template match="md:EntityDescriptor/comment()">
+		<xsl:copy/>
+	</xsl:template>
+	
+	<xsl:template match="shibmd:KeyAuthority//comment()">
+		<xsl:copy/>
+	</xsl:template>
+	
+	<!--
+		Strip all other comments.
+	-->
+	
+	<!--By default, copy text blocks and attributes unchanged.-->
+	<xsl:template match="text()|@*">
 		<xsl:copy/>
 	</xsl:template>