Personalize API now supports rcs as optional request parameter, like some other requests, e.g. recsForPlacements. It is used for identifying non-logged in users.
rcs is first party cookie string. This is a encrypted value of richrelevance cookies. It should be passed as it was received in the earlier api response.
For rcs to be returned in response, includeRcs request parameter must be set to true. includeRcs is new optional boolean request parameter.