Note: Doc team updates the current version of the documentation and the
two previous versions (n-2), but we address *only high-priority, or
customer-reported issues* for -2 releases in support.
Describe the changes in the doc and link to your dev story:

1. - [x] Mandatory: Add the required version to the Fix version/s field.

2. - [x] Mandatory: Choose the type of documentation change or review.

• [x] We need to update to an existing topic

• [x] We need to add a new document to an existing section

• [ ] We need a whole new section; this is a function not
  documented before and doesn't belong in any current section

• [ ] We need an Operator Advisory review and approval

• [ ] We need a z-Stream (Errata) Advisory and Release note for
  MCE and/or ACM

3. - [x] Mandatory: Find the link to where the documentation update
should go and add it to the recommended changes. You can either use the
published doc or the staged repo for this step:

Note: As the feature and doc is understood, this recommendation may
change. If this is new documentation, link to the section where you think
it should be placed.

Add to section:
https://docs.redhat.com/en/documentation/red_hat_advanced_cluster_management_for_kubernetes/2.13/html-single/observability/index#alert-prereqs

Configuring alert forwarding could result in restarting prometheus on OCP managed clusters. It is recommended that you configure managed cluster prometheus instances with persistent storage so metrics are not lost on the managed cluster during restart. Please see OCP documentation: https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html/monitoring/configuring-core-platform-monitoring#configuring-persistent-storage_storing-and-recording-data for configuring persistent storage

Update section:
https://docs.redhat.com/en/documentation/red_hat_advanced_cluster_management_for_kubernetes/2.13/html-single/observability/index#forward-alerts

After you enable observability, alerts from your OpenShift Container Platform managed clusters are automatically sent to the Alertmanager on the hub cluster. By default, all platform alerts are sent to alert manager on the hub cluster. When the OCP the managed cluster has user workload monitoring enabled, user workload alerts are also sent to the hub cluster. Refer to OCP documentation: https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html/monitoring/configuring-user-workload-monitoring for enabling user workload monitoring and https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html/monitoring/managing-alerts for managing alerts.

To forward user workload alerts, the alerts must be processed by user workload Prometheus instance, and not by Thanos Ruler. The user workload Prometheus requires adding a label to alerting rules in order to force only user workload Prometheus deployed in the openshift-user-workload-monitoring namespace to evaluate the alerting rule and prevents the Thanos Ruler instance from processing them. For more details, please refer to OCP documentation: https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html/monitoring/about-openshift-container-platform-monitoring#about-creating-alerting-rules-for-user-defined-projects_key-concepts

apiVersion: monitoring.coreos.com/v1
kind: PrometheusRule
metadata:
  labels:
    openshift.io/prometheus-rule-evaluation-scope: leaf-prometheus

Update section:
https://docs.redhat.com/en/documentation/red_hat_advanced_cluster_management_for_kubernetes/2.13/html-single/observability/index#disabling-forward-alerts
1.5.3.1. Disabling alert forwarding for managed clusters
When you set the annotation, both platform and user workload alerts are no longer forwarded to hub Alertmanager. The forwarding configuration on the managed clusters is reverted. Configuration updates to the ocp-monitoring-config config map in the openshift-monitoring namespace and user-workload-monitoring-config in ocp-user-workload-monitoring namespace are reverted. Setting the annotation ensures that the these config maps are no longer managed or updated by the observability operator endpoint. After you update the configuration, both plaform and user workload Prometheus instances on your managed will cluster restart.

Add new section:
1.5.3.2. Disabling user workload alert forwarding for managed clusters
To disable alert forwarding for managed clusters, add the following annotation to the MultiClusterObservability custom resource:

metadata:
  annotations:
    mco-disable-uwl-alerting: "true"

When you can you set the annotation, the user workload alerts will no longer be forward user workload alerts are no longer forwarded to hub Alertmanager, while platform alerts continue to be forwarded. Setting the annotation ensures that the user-workload-monitoring-config config map is no longer managed or updated by the observability operator endpoint. After you update the configuration, the user workload Prometheus instance on your managed cluster restarts.

Customer Portal published version

https://docs.redhat.com/en/documentation/red_hat_advanced_cluster_management_for_kubernetes/2.12

Doc staged repo within the ACM Workspace:
https://github.com/stolostron/rhacm-docs

4. - [ ] Mandatory for GA content:

• [ ] Add steps, the diff, known issue, and/or other important
  conceptual information in the following space:

• [ ] *Add Required access level *(example, *Cluster
  Administrator*) for the user to complete the task:

• [ ] Add verification at the end of the task, how does the user
  verify success (a command to run or a result to see?)

• [x] Add link to dev story here:

https://issues.redhat.com/browse/ACM-21198

5. - [ ] Mandatory for bugs: What is the diff? Clearly define what the
problem is, what the change is, and link to the current documentation. Only
use this for a documentation bug.
This is identified as a bug in a feature that is available in ACM 2.14.0 release only (yet to be released).