Hi Jones, Since aam_uuid gets written as a first party cookie but by third party domain, so it's in third party context, and Safari should delete that in 24 hours. But, with cname implemented for ID service, there is no harm in keeping aam_uuid as well.Just make sure that you have s_ecid cookie being set as first party:https://docs.adobe.com/content/help/en/id-service/using/reference/ecid-library-methods.html Thanks,Varun Kalra