Update br/backup-and-restore-faq.md

br/backup-and-restore-faq.md

@@ -22,7 +22,7 @@ To reduce the impact on the cluster, you can use the `--ratelimit` parameter to
 
 ## Does BR back up system tables? During data restoration, do they raise conflict?
 
-Before v5.1.0, BR filtered out data from the system schema mysql during the backup. Since v5.1.0, BR backs up all data by default, including the system schemas mysql.*. But the technical implementation of restoring the system tables in mysql.* is not complete yet, so the tables in the system schema mysql are not restored by default. For more details, refer to the [Back up and restore table data in the mysql system schema](/br/backup-and-restore-tool.md#back-up-and-restore-table-data-in-the-mysql-system-schema-experimental-feature).
+Before v5.1.0, BR filtered out data from the system schema `mysql` during the backup. Since v5.1.0, BR **backs up** all data by default, including the system schemas `mysql.*`. But the technical implementation of restoring the system tables in `mysql.*` is not complete yet, so the tables in the system schema `mysql` are **not** restored by default. For more details, refer to the [Back up and restore table data in the `mysql` system schema (experimental feature)](/br/backup-and-restore-tool.md#back-up-and-restore-table-data-in-the-mysql-system-schema-experimental-feature).
 
 ## What should I do to handle the `Permission denied` or `No such file or directory` error, even if I have tried to run BR using root in vain?