By default, profiles and custom resources have no business ID when they are created. You can enable an option that generates automatically a unique ID when elements are created. This ID can be used to:
The ACS ID field is now available and automatically populated when new elements are created manually, from the API, or inserted from an import workflow. The ACS ID field is a UUID field and is indexed.
When exporting profiles or custom resources, you can now add the ACS ID column if it has been enabled for that resource. You can reuse this ID in your external tools to identify records.

When re-importing data that have been processed/updated in another application (for example a CRM), you can reconcile it easily with this unique ID.
Nota:
The ACS ID field: is not updated for profiles or elements created before activating the option. Only new records will have and ACS ID. is in read-only mode. You cannot modify it.