https://wiki.mozilla.org/Firefox_Security_Newsletter/FSN-2021-Q1
> Total Cookie Protection in Enhanced Tracking Protection’s Strict Mode: Starting in Firefox 86, Firefox users browsing the web in ETP’s Strict-Mode can benefit from a privacy feature named Total Cookie Protection.

https://wiki.mozilla.org/Firefox_Security_Newsletter/FSN-2022-Q1
> Usability and Tracking Protection: Firefox 96 also shipped improved Service Worker isolation as part of our work towards Total Cookie Protection (formerly known as Dynamic First Party Isolation).