=/v1.18/docs/ops/integrations/prometheus#option-2-metrics-merging/>operations guide for Prometheus</a>.</li><li><em><strong>Added</strong></em> the ability for mesh operators to add and remove labels used in Istio metrics, based on expressions over the set of available request and response attributes. This improves Istio&rsquo;s support for <a href=/v1.18/docs/tasks/observability/metrics/customize-metrics/>customizing v2 metrics generation</a>.</li><li><em><strong>Updated</strong></em> default telemetry v2 