originally http://bugs.musicbrainz.org/ticket/3373 but the link mentioned there isn't on that page anymore. I found another example, the download link on http://wiki.musicbrainz.org/User:PBryan/metatool it works there, but on http://test.musicbrainz.org/doc/User:PBryan/metatool you get a 404 which is misleading (the ticket in trac has more discussion about what we should do)