https://learn.microsoft.com/en-us/uwp/api/windows.foundation.metadata.deprecatedattribute?view=winrt-10240
DeprecatedAttribute Class (Windows.Foundation.Metadata) - Windows apps | Microsoft Learn
Indicates that a type or member should be marked in metadata as deprecated. Compilers and other developer tools can read this attribute and provide info to the...
classwindowsfoundationmetadataapps