Open Radar

 
Summary:
There is no documentation for Objective-C’s header documentation as parsed by Xcode anywhere on the developer website.

Steps to Reproduce:
Google “headerdoc documentation” see no official documentation in the results
Search for HeaderDoc on https://developer.apple.com/
Search for HeaderDoc on https://developer.apple.com/library/ios/navigation/ or https://developer.apple.com/library/mac/navigation/
Go to http://developer.apple.com/opensource/tools/headerdoc.html, get redirected to https://developer.apple.com/library/mac/documentation/DeveloperTools/Conceptual/HeaderDoc/intro/intro.html, which is a 404
Search for HeaderDoc in Xcode 7.3.1 documentation viewer

Expected Results:
https://developer.apple.com/library/mac/documentation/DeveloperTools/Conceptual/HeaderDoc/intro/intro.html shows documentation

Actual Results:
There is no documentation available for HeaderDoc

Regression:
Since Wikipedia still points to http://developer.apple.com/opensource/tools/headerdoc.html, I assume it used to work.

Notes:
While the Markup Formatting Reference at https://developer.apple.com/library/ios/documentation/Xcode/Reference/xcode_markup_formatting_ref is useful, it only applies to Swift code, and thus the HeaderDoc reference is still needed.