I recently observed an issue with the dispatcher rewrite rules wherein the rules put in and having french accented characters / special character like single quote in the source url seems to be failing. It goes to a 404.
The ACS commons redirect map is being used. And i do see the NE flag on the line where the redirect map is mapped to the dispatcher. However that is not working as expected.
Note : there are files having space in the filenames so multiple entries in the file have a %20 in the source url as well