Tab is a Search API query parameter whose value is the name or identifier of the tab from which the query originates.

When the tab is specified in a query, the origin level 2 field of the corresponding Search usage analytics event is typically populated with identical data to allow Coveo Machine Learning (Coveo ML) models to learn from that contextual information from which the query originates.

Don’t confuse this with the Coveo JavaScript Search Framework tab component.