In the filter definition, you can specify the blacklist or whitelist keyword after the resource. A blacklisted filter will block the corresponding cluster events. This means that the cluster events won't be delivered on the cluster. On the other hand, a whitelisted filter will allow the corresponding cluster events. The filter is built by evaluating the whitelist first and by overriding the blacklist later. With the combination of blacklist and whitelist filters, you can define fine-grained filtering.