CUPS version: 2.2.10

1. Enter lpadmin -p {printer-name} -D ''-> 'Info' in '/etc/cups/printers.conf' become blank .
2. when I enter lpoptions -p {printer-name} , 'printer-info' is printed.
3. cups restart or reboot.
4. 'Info' still is blank.
5. but, when I enter lpoptions -p {printer-name} , 'printer-info={printer-name}' is printed.

How can I avoid 'printer-info' is set to 'printer-name' automatically?