Hi, I found this magic string for Cyrus skiplist in http://www.invoca.ch/pub/packages/cyrus-imapd/scripts/convertdb/, it's more precise than the one provided by Sven Mueller.
Regards -- Farzad FARID <[EMAIL PROTECTED]> http://www.farzy.org/
# Magic # Magic data for file(1) command. # Format is described in magic(files), where: # files is 5 on V7 and BSD, 4 on SV, and ?? in the SVID. #------------------------------------------------------------------------------ # skiplist: file(1) magic Cyrus skiplist DB # 0 string \241\002\213\015skiplist\ file\0\0\0 Cyrus skiplist DB