HP Fortran Programmer's Reference (September 2007)

I/O and file handling
Binary I/O Conversions (for Itanium‚—based systems)
Chapter 8226
Typically, code is written via the CONVERT=argument to OPEN and INQUIRE. Therefore,
this option was given the higher priority status to allow overriding “normal” coding via the
environment variable.
NOTE The CONVERT parameter to OPEN is only available via f90 version 2.7 or
later, and is only accepted for UNFORMATTED files.