The s_objectID variable provides a unique identifier for a link. It is used to make reports in Activity Map more accurate. If you have links on a page that frequently change, you can use the s_objectID variable to tell Activity Map of a unique link location so it can correctly group data as desired.
If Activity Map accuracy is crucial to your organization, Adobe recommends including the s_objectID variable in the onClick event of links on your site. See Activity Map link tracking use cases in the Analyze user guide for more information.
Object ID in Adobe Experience Platform Launch
There is not a dedicated field in Launch to use this variable. Use the custom code editor, following AppMeasurement syntax.
s_objectID in AppMeasurement and Launch custom code editor
The s_objectID variable is a global variable, meaning that it operates independently of the Analytics tracking object ( s by default). Valid values for this variable can be any string up to 100 bytes in length. If this variable is not defined, Activity Map uses the link URL as the identifier for the link.
This variable is typically set in the onClick event of an HTML link.
<a href="https://example.com" onClick="s_objectID='Example identifier';">Example link</a>
The s_objectID variable is valuable whenever you want increased accuracy in Activity Map reporting.