We assume that conventions exist for programs written in one language to call routines written in another language. These conventions specify how to link routines in different languages into one program, how to call functions in a different language, how to pass arguments between languages, and the correspondence between basic data types in different languages. In general, these conventions will be implementation dependent. Furthermore, not every basic datatype may have a matching type in other languages. For example, C character strings may not be compatible with Fortran CHARACTER variables. However, we assume that a Fortran INTEGER, as well as a (sequence associated) Fortran array of INTEGERs, can be passed to a C program. We also assume that Fortran and C have address-sized integers. This does not mean that the default-size integers are the same size as default-sized pointers, but only that there is some way to hold (and pass) a C address in a Fortran integer. It is also assumed that INTEGER(KIND=MPI_OFFSET_KIND) can be passed from Fortran to C as MPI_Offset.