Our deprecation policy is a very simple three step process.
Firstly APIs to be removed must be marked with the Obsolete attribute with the boolean parameter set to false such that the code can still be used. The warning message should direct users to alternative/replacement APIs that are available and when we expect to remove the API.
There must be at least one release where this is present and the change must be noted in the Change Log for that release.
If the API is included in any documentation on the website it should be updated to indicate that the API is being deprecated or to use the alternative APIs
In a release subsequent to the Obsolete attribute having been added the boolean parameter must be set to true so that using this code now results in a compiler error. The warning message may be updated to further clarify alternative/replacement APIs and when we will remove the API.
Again there must be at least one release where this is present and the change must be noted in the Change Log for that release. Ideally an API should only remain in this state for a single release.
If the API is included in any documentation on the website it must be updated to indicate that the API is obsolete and documentation is preserved only for historical reference.
The API must be fully removed from the library and this must be noted in the Change Log of the release where this happens.
Documentation pertaining to this API must be removed or clearly marked as pertaining to an obsolete unsupported API.