|If this file was produced on VMS, it is most probably a VMS BACKUP saveset.|
try BACKUP/LIST file.bak/SAVE
If it gives You an error, it can still be a backup file, but having wrong record attributes due to some (network-)transfer.
Try to find one of the fix_saveset programs on the net, like
(for Alpha only), or
Newer VMS versions have BACKUP/REPAIR , try that.
File extensions in VMS are arbitrary, so a .bak file can of course be anything else.
On unix and windows systems .bak files are often editor "backup" files.
Joseph Huber, http://www.huber-joseph.de