Every API file has a stability rating from 0 to 5 in its header indicating how stable the contents are. Those ratings are explained in this file.
This feature is known to be problematic, and changes are planned. Do not rely on it. Use of the feature may cause warnings. Backwards compatibility should not be expected.
This feature was introduced recently, and may change or be removed in future versions. Please try it out and provide feedback. If it addresses a use-case that is important to you, tell the node core team.
The API is in the process of settling, but has not yet had sufficient real-world testing to be considered stable. Backwards-compatibility will be maintained if reasonable.
The API has proven satisfactory, but cleanup in the underlying code may cause minor changes. Backwards-compatibility is guaranteed.
This API has been tested extensively in production and is unlikely to ever have to change.
Unless serious bugs are found or mojang changes the underlying system, this code will not ever change. Please do not suggest changes in this area, they will be refused.