It is used to create a tab in the login page
Example code
CPropertySheet* pAddLoginUserPages=(CPropertySheet*)pSheet.byref; CComPtr<ISmpPluginTab> SmpPluginTab; SmpPluginTab.CoCreateInstance(CLSID_SmpPluginTab); VARIANT Var; Var.vt=VT_BYREF; Var.byref=m_SMPUserEventDlg; SmpPluginTab->AddSmpPage(Var); return S_OK;