Nevertheless it is recommended not to store ReiserFS v3 images on a ReiserFS v3 partition (e.g. backups or disk images for emulators) without transforming them to a form that avoids misleading the filesystem, e.g., by compressing or encrypting. Reformatting an existing ReiserFS v3 partition can also leave data behind that could confuse the rebuild operation, resulting e.g. in files from the old filesystem reappearing after a tree rebuild. Note that this also opens an opportunity for malicious users to intentionally store files that will confuse the rebuilder. As the metadata is always in a consistent state after a filesystem check, corruption here means contents of files being merged in unexpected ways with the contained filesystem's metadata. The ReiserFS successor, Reiser4, fixes this problem.