Why did Windows NT decline to support an undocumented flag to TrackPopupMenuEx?
Commenter kero points out that Windows 95 supported a flag called
TPM_SYSMENU, but Windows NT doesn’t. Why not?
TPM_SYSMENU was never documented. It was used internally by Windows 95 for something-or-other, but Windows NT didn’t need to support it, so it didn’t. Since it was an internal flag that was never documented, the Windows NT team were under no obligation to support it, and they chose not to. After all, why go to the extra work of writing code to support a flag that nobody can legitimately be using?
Unsupported flag is unsupported.