This is the repository for Fenced Frames.
See the draft specification.
The explainer is organized as follows:
What is a fenced frame: the concept, HTML element, security and privacy considerations
What are the problems being solved/ different modes of fenced frames?
Deep dive in the "opaque-ads" use case which will be the first launch of fenced frames
How fenced frames integrates with the web platform. This is a growing list of things and will be added to the documentation