docs/react-v9/contributing/rfc-process.md
An RFC is usually an ongoing pull request with a single mark down file and supporting assets that serves as a discussion point to drive towards consensus around a new technical or process idea. We put these documents in the rfcs folder that serves as an archive.
The React RFC Process sums it up nicely
The RFC process is a great opportunity to get more eyeballs on your proposal before it becomes a part of a released version. Quite often, even proposals that seem "obvious" can be significantly improved once a wider group of interested people have a chance to weigh in.
The RFC process can also be helpful to encourage discussions about a proposed feature as it is being designed, and incorporate important constraints into the design while it's easier to change, before the design has been fully implemented.
A key purpose of the review phase is to seek feedback to help improve your idea. You the author are ultimately accountable for the proposal and its impact. Reviewers can, through comments, help you make the best decision you can. Throughout this review and process it is important that we strive to avoid both Design by Committee and Diffusion of Responsibility.
Following the theme of author accountability, in general it's up to the author to decide when they feel they have received enough feedback, and enough approvals to proceed.