, any operation is allowed.</p></td><td>No</td></tr><tr id=Rule-when><td><code>when</code></td><td><code><a href=#Condition>Condition[]</a></code></td><td><p>Optional. when specifies a list of additional conditions of a request.</p><p>If not set, any condition is allowed.</p></td><td>No</td></tr></tbody></table></section><h2 id=Rule-From>Rule.From</h2><section><p>From includes a list or sources.</p><table class=message-fields><thead><tr><th>Field</th><th>Type</th><th>Description</th><th>Required</th></tr></