New -as mkisofs option -disallow_dir_id_ext, allow_dir_id_ext is default

xorriso/xorriso.texi

@@ -4160,6 +4160,11 @@ standard output.
 -print-size inhibits automatic image production at program end. This ban is
 lifted only if the pending image changes get discarded.
 @*
+If no -iso-level is given, then level 1 is chosen when the first file or
+directory is added to the image. At the same occasion directory names get
+allowed to violate the standard by -compliance option allow_dir_id_ext.
+This may be avoided by option -disallow_dir_id_ext.
+@*
 Not original mkisofs options are @minus{}@minus{}quoted_path_list ,
 @minus{}@minus{}hardlinks , @minus{}@minus{}acl ,
 @minus{}@minus{}xattr , @minus{}@minus{}md5 , @minus{}@minus{}stdio_sync .