diff --git a/format-master.xml b/format-master.xml
index 5fbadb6..a711686 100755
--- a/format-master.xml
+++ b/format-master.xml
@@ -288,6 +288,80 @@
 		</html>
 	</template>
 
+	<!--
+		Generate a left, right or full outer join operator.
+		
+		@type: the type of outer join operator [optional]
+			'left'
+			'right'
+			'full'	[default]
+	-->
+	<template name="outer-join-operator" match="outer-join-operator|outer-join">
+		<latex>
+			<xsl:text>\ensuremath{\</xsl:text>
+			<xsl:choose>
+				<xsl:when test="@type">
+					<xsl:value-of select="@type"/>
+				</xsl:when>
+				<!-- default to a full outer join -->
+				<xsl:otherwise>
+					<xsl:text>Full</xsl:text>
+				</xsl:otherwise>
+			</xsl:choose>
+			<xsl:text>OuterJoin}</xsl:text>
+		</latex>
+		<!--
+			No easy way at present to get a join symbol in HTML, so
+			just use an image. Scale it to 10 pixels high (fine as long as
+			font size is set relatively normally, width depends on operator
+			type).
+			
+			We need to ensure that the path is absolute, because we don't
+			necessarily know where the document will end up in the tree.
+		-->
+		<html>
+			<IMG>
+				<xsl:attribute name="SRC">
+					<xsl:text>/</xsl:text>
+					<xsl:value-of select="$department"/>
+					<xsl:value-of select="$paper"/>
+					<xsl:text>/Handbook/</xsl:text>
+					<xsl:choose>
+						<xsl:when test="@type">
+							<xsl:value-of select="@type"/>
+						</xsl:when>
+						<!-- default to a full outer join -->
+						<xsl:otherwise>
+							<xsl:text>full</xsl:text>
+						</xsl:otherwise>
+					</xsl:choose>
+					<xsl:text>-outer-join-operator-web.png</xsl:text>
+				</xsl:attribute>
+				<xsl:attribute name="ALT">
+					<xsl:text>Join operator</xsl:text>
+				</xsl:attribute>
+				<xsl:attribute name="WIDTH">
+					<xsl:choose>
+						<xsl:when test="(@type = 'left') or (@type = 'right')">
+							<xsl:text>15</xsl:text>
+						</xsl:when>
+						<!-- default to a full outer join -->
+						<xsl:otherwise>
+							<xsl:text>20</xsl:text>
+						</xsl:otherwise>
+					</xsl:choose>
+					<xsl:text>10</xsl:text>
+				</xsl:attribute>
+				<xsl:attribute name="HEIGHT">
+					<xsl:text>10</xsl:text>
+				</xsl:attribute>
+				<xsl:attribute name="STYLE">
+					<xsl:text>padding-left:0.3em;padding-right:0.3em</xsl:text>
+				</xsl:attribute>
+			</IMG>
+		</html>
+	</template>
+
 	<template name="intersect-operator" match="intersect-operator|intersect|intersection|cap">
 		<latex>\ensuremath{\cap}</latex>
 		<html><xsl:text disable-output-escaping="yes">&amp;#8745;</xsl:text></html>
