Man pages matching name backend in section 7:

backend.7.de	debian 10 / cups-daemon
backend.7.en	debian 10 / cups-daemon
backend.7.fr	debian 10 / cups-daemon
backend.7.de	debian 11 / cups-daemon
backend.7.en	debian 11 / cups-daemon
backend.7.de	debian 12 / cups-daemon
backend.7.en	debian 12 / cups-daemon
backend.7.fr	debian 12 / cups-daemon
backend.7.pt	debian 12 / cups-daemon