input_file_name
    OpenVMS usage:descriptor
    type:         character string
    access:       read
    mechanism:    by reference
    The name of the input file.
 context
    OpenVMS usage:context
    type:         longword (unsigned)
    access:       modify
    mechanism:    by reference
    Pointer to site's local context.
 write_fao (fao_string[,arg1[,arg2][,...]]])
    OpenVMS usage:routine
    type:         procedure
    access:       read
    mechanism:    by reference
    Address of a routine that may be called to format and display
    output. The routine has fao_string as its first argument,
    followed by a variable number of arguments. (See the $FAO system
    directive in the HP OpenVMS System Services Reference Manual for
    more information.)