deploy: 1e67191a79

develop/print.html

@@ -4709,6 +4709,10 @@ N.B. we recommend also firewalling your federation listener to limit
 inbound federation traffic as early as possible, rather than relying
 purely on this application-layer restriction.  If not specified, the
 default is to whitelist everything.</p>
+<p>Note: this does not stop a server from joining rooms that servers not on the
+whitelist are in. As such, this option is really only useful to establish a
+&quot;private federation&quot;, where a group of servers all whitelist each other and have
+the same whitelist.</p>
 <p>Example configuration:</p>
 <pre><code class="language-yaml">federation_domain_whitelist:
   - lon.example.com

develop/usage/configuration/config_documentation.html

@@ -1163,6 +1163,10 @@ N.B. we recommend also firewalling your federation listener to limit
 inbound federation traffic as early as possible, rather than relying
 purely on this application-layer restriction.  If not specified, the
 default is to whitelist everything.</p>
+<p>Note: this does not stop a server from joining rooms that servers not on the
+whitelist are in. As such, this option is really only useful to establish a
+&quot;private federation&quot;, where a group of servers all whitelist each other and have
+the same whitelist.</p>
 <p>Example configuration:</p>
 <pre><code class="language-yaml">federation_domain_whitelist:
   - lon.example.com