From
http://wiki.etree.org/index.php?page=FlacFingerprint :
A FLAC Fingerprint is a small text file (ffp.txt) that contains the filename and the checksum information for one or more .flac files. The fingerprint is analogous to yet somewhat different from the .md5 files for used for Shorten (.shn):
* Unlike an .md5 file, the FLAC Fingerprint ffp.txt file itself is not actually used in performing integrity checks on .flac files. Instead, when you decompress or use flac's Test feature, FLAC automatically verifies each file against an internal checksum stored in the file.