A custom attribute is any extra information that you want to send to Genesys Predictive Engagement through a call to ac ('record').

For example, an e-commerce site might add a 'packageDeliveryStatus' attribute to segment visitors whose packages have been shipped.

When you create action maps, segments, and outcomes, you can use custom attributes to tailor the system's behavior for your business.
If you are creating a custom attribute for a web event, each expression can include only a single value (one string). You cannot create an expression that uses a list of values.
For more information, see Track custom attributes with ac ('record').