pan></div></div></div></div><div class="qm-api-collapsible-content"><div class="qm-api-item-content"><div class="qm-api-description"><div class="qm-html-paragraph">The namespace to register the handler under. Namespaces isolate groups of handlers. Handlers can be removed by namespace without affecting handlers in other namespaces. The value &quot;default&quot; is reserved and may not be used as a namespace name. </div></div></div></div></div><div class="qm-api-item qm-api-javascript-arg qm-api-collapsible">