For a prerun-time array, enter array input data into a file. The file must be a sequential program described file. During initialization, but before any input, calculation, or output operations are processed the array is loaded with initial values from the file. By modifying this file, you can alter the array’s initial values on the next call to the program, without recompiling the program. The file is read in arrival sequence. The rules for prerun-time array data are the same as for compile-time array data, except there are no restrictions on the length of each record. See Rules for Array Source Records.