Geoff Chappell - Software Analyst
The IDocNavigate methods are (as ordered in the virtual function table after the IUnknown methods):
HRESULT OnReadyStateChange (IShellView *, ULONG);
HRESULT get_ReadyState (ULONG *);
The IDocNavigate interface is implemented in SHDOCVW version 4.71 to 6.0, and IEFRAME version 7.0 and higher.
Though this interface dates from as long ago as 1997, it was still not documented by Microsoft as late as the January 2004 edition of the MSDN Library on CD.