Just one slight editing in the rationale's text:
\begin{rationale}
Although it may seem desirable to impose stronger
restrictions on the type matching between file data and file
views, doing so would require implicitly defining the type of each
element in a file. Unlike variables in a program, data in a file
typically has no type independent of what an MPI read or write
operation imposes on it. It would be possible to require that
the MPI datatype used to read a file must match the MPI datatype that was
used to write it, but this would make it erroneous to read any file
not written by MPI, and it would not account for the possibility
that programs might read and write a file using different data
representations.
\end{rationale}
In addition, I would replace all occurrences of READ and WRITE with read
and write, respectively.
Jean-Pierre