--- a/4.4/dtd/docbook.dcl	2005-01-27 14:59:49.000000000 +0100
+++ b/4.4/dtd/docbook.dcl	2005-08-17 13:48:37.000000000 +0200
@@ -61,8 +61,8 @@
 	NAMING
 		LCNMSTRT ""
 		UCNMSTRT ""
-		LCNMCHAR ".-_"
-		UCNMCHAR ".-_"
+		LCNMCHAR ".-_:"
+		UCNMCHAR ".-_:"
 		NAMECASE
 			GENERAL YES
 			ENTITY  NO