Address review comments

docs/modules/fault-tolerance/pages/backups.adoc

@@ -9,13 +9,11 @@ for more information about the partitioning.
 
 [IMPORTANT]
 ====
-Hazelcast does not support backup redistribution on data structure level. For example, for a map with a nonzero backup count,
+Hazelcast does not support backup redistribution on a data structure level. Thus, changing the backup count of a nonempty data structure is **not** supported. For example, for a map with a nonzero backup count:
 
-1. increasing the backup count does **not** create additional copies of existing map entries,
-2. decreasing the backup count does **not** remove any backups of existing map entries, so some backups will have stale data if the map entries are overwritten, and
+1. increasing the backup countfootnote:change-backup-count[The backup count of a map can only be changed by modifying the xref:configuration:understanding-configuration.adoc#static-configuration[static configuration] and restarting the cluster.] does **not** create additional copies of existing map entries,
+2. decreasing the backup countfootnote:change-backup-count[] does **not** remove any backups of existing map entries, so some backups will have stale data if the map entries are overwritten, and
 3. if some backups are lost due to node failure, additional copies are **not** created on other nodes to meet the backup count.
-
-Thus, it is unsupported to change the backup count of a data structure once it was populated with data.
 ====
 
 When a member in your cluster is lost, Hazelcast redistributes the backups