diff --git a/format-master.xml b/format-master.xml
index feb0ad6..efefc4e 100755
--- a/format-master.xml
+++ b/format-master.xml
@@ -4277,7 +4277,9 @@
 			<xsl:variable name="digit-separator">
 				<xsl:text disable-output-escaping="yes">&amp;thinsp;</xsl:text>
 			</xsl:variable>
-			<!-- Recursively subdivide the sequence. Terminate when sequence length <= 3. -->
+			<!--
+				Recursively subdivide the sequence. Terminate when sequence length <= 3. Note that we have to use the numeric entity for thin space rather than the character entity &thinsp; because of the weird way XSLT handles character entities. Using the character entity, the HTML visibly displays as "&thinsp;".
+			-->
 			<xsl:sequence select="
 				if ( string-length( $unseparated-value ) > 3 )
 				then concat(