This section defines the rules for MPI language binding in general and for Fortran, and ISO C, in particular. (Note that ANSI C has been replaced by ISO C.) Defined here are various object representations, as well as the naming conventions used for expressing this standard. The actual calling sequences are defined elsewhere.
MPI bindings are for Fortran 90 or later, though they were originally designed to be usable in Fortran 77 environments. With the mpi_f08 module, two new Fortran features, assumed type (i.e., TYPE(*)) and assumed rank (i.e., DIMENSION(..)), are also required, see Section Choice.
Since the word PARAMETER is a keyword in the Fortran language, we use the word ``argument'' to denote the arguments to a subroutine. These are normally referred to as parameters in C, however, we expect that C programmers will understand the word ``argument'' (which has no specific meaning in C), thus allowing us to avoid unnecessary confusion for Fortran programmers.
Since Fortran is case insensitive, linkers may use either lower case or upper case when resolving Fortran names. Users of case sensitive languages should avoid any prefix of the form ``MPI_'' and ``PMPI_'', where any of the letters are either upper or lower case.