A system device. It can be a disk drive, the display, a printer, or an RS232 port. If you include filename, device must be a disk drive. The COBOL system recognizes the following symbolic device names:
| A, B, ...Z | Disk drive |
| CON | Console keyboard or screen |
| AUX, COM1, PUN | Alternative names for the first asynchronous communications adapter port |
| COM2 | Second asynchronous communications port |
| LPT1, LPT, LST, PRN | Alternative names for the first parallel printer |
| LPT2, LPT3, LPTn | Second, third and subsequent parallel printers |
| ERR | Standard Error Output |
| NUL | Dummy device - do not create (not available with indexed files) |