One para explanation of the proposal.
Why are we doing this? What use cases does it support? What is the expected outcome?
This is the bulk of the RFC. Explain the design in enough detail for somebody familiar with the project to understand and implement. This should get into specifics and corner-cases, and include examples of how the feature is used.
Why should we not do this?
What other designs have been considered? What is the impact of not doing this?
What parts of the design are still TBD?