Agent Client Collector (ACC) Discovery Source values in the CMDBThe Agent Client Collector Framework (ACC-F), when a newly installed agent is first started up, will need to do a basic Discovery of the host it's installed on and create a computer/server CI in the CMDB linked to it. This is done even if Discovery is not installed in the instance, because the other features that use ACC-F usually need a CI to either bind events/alerts/metrics to for Monitoring or Health Log Analytics, or to bind Incidents to for Security Incident Response, etc... If the "Discovery" plugin and "Agent Client Collector for Visibility" app (ACC-V) is installed, then the behaviour of this self-discovery changes. In addition to that basic discovery, ACC-V records software installs, storage, running processes, etc... Given that design, you can possibly expect to see 2 different Discovery Source values used for the computer CIs in the same instance: AgentClientCollectorWhen the ACC was initially discovered by the "check-discovery-basic" check, that's part of ACC-F.ACC-VisibilityWhen Discovery and ACC-V are installed, and "Enhanced Discovery Policy" periodically runs the "Enhanced Discovery" check, if the Agent is covered by the filter of that policy. If other Discovery Sources, such as IP-based/horizontal Discovery, Service mapping, Service Graph Connectors, or other imports/integrations are also updating the same computer CIs, you can expect the CIs to have discovery source values corresponding to those some of the time too. The Discovery Source value is usually updated to show which source was the one that most recently updated the CI. The CMDB Identification and Reconciliation Engine (IRE) tends not to use this field at a record-level any more, and instead uses other field-level tracking tables for reconciliation. Subscription usage/license counting uses these values. A CI with "ACC-Visibility" is counted towards a Discovery or ITOM Visibility subscription, at a lower node count weighting that a full Discovery with discovery source "ServiceNow" (4:1 as of Q1 2022), but the basic discovery by "AgentClientCollector" is not counted in those totals.