When integrated with Raiser's Edge, soft credits in Luminate Online are the same thing as solicitors in The Raiser's Edge.

If you have a constituent registered as a TeamRaiser participant and another constituent makes a donation on that participant's personal page, the gift will be soft credited to the participant. This is because the gift came to the event by way of this participant.

The participant's constituent record in The Raiser's Edge will then be the solicitor of that gift.