The READWRITE specifier asks whether a file can be both read and written to. It takes the following form:
READWRITE = rdwr
rdwr
Is a scalar default character variable that is assigned one of the following values:
| 'YES' | If the file can be both read and written to |
| 'NO' | If the file cannot be both read and written to |
| 'UNKNOWN' | If the processor cannot determine whether the file can be both read and written to |