The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.

The latest version of this topic can be found at C28216.

warning C28216: The _Check_return_ annotation only applies to post-conditions for the specific function parameter.

The _Check_return_ annotation has been applied in a context other than __post; it may need a __post (or __drv_out) modifier, or it may be placed incorrectly.