Add also xhtml1 dtd to local catalog
diff --git a/lib/dtds/xhtml/dtd/xhtml.soc b/lib/dtds/xhtml/dtd/xhtml.soc
new file mode 100644
index 0000000..0624dea
--- /dev/null
+++ b/lib/dtds/xhtml/dtd/xhtml.soc
@@ -0,0 +1,14 @@
+OVERRIDE YES
+ -- Oasis entity catalog for Extensible HTML 1.0 --
+
+PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "xhtml1-strict.dtd"
+PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd"
+PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN" "xhtml1-frameset.dtd"
+
+ -- ISO latin 1 entity set for Extensible HTML (XML 1.0 format) --
+
+PUBLIC "-//W3C//ENTITIES Latin 1 for XHTML//EN" "xhtml-lat1.ent"
+PUBLIC "-//W3C//ENTITIES Symbols for XHTML//EN" "xhtml-symbol.ent"
+PUBLIC "-//W3C//ENTITIES Special for XHTML//EN" "xhtml-special.ent"
+
+SGMLDECL "xhtml1.dcl"