Bid Event Interest Invitation Emails on Public Event

Please provide more specifics on when, and to whom, Event Interest Invitation emails go out.

Delivered Workflows for PeopleSoft Strategic Sourcing states that the Event Interest Invitation, “Notifies noninvited bidders that a public event was posted in which they may be interested based on their self-categorization preferences.”

For example, when a public bid event is created should the category code associated to it cause the Event Interest Invitation to go out upon posting to any bidders & suppliers who have selected that category code and are associated to it on the AUC_BID_SLF_CAT table?

For bidders, who should receive this Event Interest Invitation, all contacts, just the primary, email on the address, etc.? And I would assume only approved bidder should receive this email?