Setting this value to "1" (on, true, yes) causes the transaction management system to assume that the log file is actually a device, rather than a file. This means that a special device locking method will be used on the log file (see the ACUCOBOL-GT User's Guide section 6.1.5 , "Device Locking Under UNIX"). It also guarantees that the log file will be opened "append" and that no seeks will be performed on it. This allows for the use of a tape device for the log file on many systems. The default setting is "0" (off, false, no).