An annotation for APIs which configure QUICHE options not curated by Cronet.
APIs annotated by this are considered stable from Cronet's perspective. However, they simply pass the configuration options to QUICHE, a library that provides the HTTP3 implementation. As the dependency is under active development those flags might change behavior, or get deleted. The application accepts the stability contract as stated by QUICHE. Cronet is just a mediator passing the messages back and forth.
Cronet provides the APIs as a compromise between customer development velocity (some customers value access to bleeding edge QUICHE features ASAP), and Cronet's own interests (stability and readability of the API, capacity to propagate new QUICHE changes). Most Cronet customers shouldn't need to use those APIs directly. Mature QUICHE features that are generally useful will be exposed by Cronet as proper top level APIs or configuration options.