As part of the United States v. Microsoft Corp. settlement, Microsoft had to document the "secret" APIs they used in Internet Explorer so third party developers could use them as well.
I remember there was a website with a list of those APIs. Anybody knows where it could be?
⇒ chances are Microsoft removed the info from their website.
There is https://docs.microsoft.com/en-us/openspecs/windows_protocols..., though. Reading https://queue.acm.org/detail.cfm?id=1996412, it seems that’s what that evolved into.