Make doc sigles even safer
diff --git a/xslt/epub2i5.xsl b/xslt/epub2i5.xsl
index 0c93a14..685c276 100644
--- a/xslt/epub2i5.xsl
+++ b/xslt/epub2i5.xsl
@@ -200,7 +200,7 @@
</xsl:otherwise>
</xsl:choose>
</xsl:variable>
- <xsl:value-of select="substring(replace(normalize-unicode(concat($authorInitials,$firstContentWordTitleInitial), 'NFKD'),'\P{ASCII}',''),1,3)"/>
+ <xsl:value-of select="substring(replace(normalize-unicode(concat($authorInitials,$firstContentWordTitleInitial), 'NFKD'),'[^A-Z]',''),1,3)"/>
</xsl:variable>