[Home](./index.md) > [fastify-metrics](./fastify-metrics.md) > [IRouteMetricsConfig](./fastify-metrics.iroutemetricsconfig.md) > [invalidRouteGroup](./fastify-metrics.iroutemetricsconfig.invalidroutegroup.md) ## IRouteMetricsConfig.invalidRouteGroup property Unknown route label. If registeredRoutesOnly routes set to `false` unknown routes will have following url. **Signature:** ```typescript invalidRouteGroup?: string; ``` ## Default Value `__unknown__`