- Only needed for rest-server repos that distinguish an append-only - user (everyday backups) from a delete-capable user (prune / - forget). For S3 / B2 / SFTP / local, leave this blank — the - everyday repo credentials handle prune too. + Required for prune. On rest-server repos this is the + delete-capable user, as distinct from the append-only user used + for everyday backups. Note that forget always + runs with the everyday repo credentials, so those must have + delete authority. For S3 / B2 / SFTP / local, enter the same + delete-capable repository credentials here if you want prune + enabled. Prune is skipped when admin credentials are + unset, on any backend.