Lets you enter a property description and property DISPID, and provide a callback function to determine whether any CLSID should be added to the property map.
Include this macro to give an application more control over the IPersistStreamInitImpl::Load process. The callback function pfnFunc is called when IPersistStreamInitImpl::Load is retrieving data from a non-trusted stream. The callback function filters the data and controls which objects are loaded.
This macro only applies if IPersistStreamInitImpl is a base class and the class is advertised as safe for initializing. Otherwise, you should not use this macro.
This macro is only valid if vt is VT_DISPATCH or VT_UNKNOWN. Passing in a different value for vt to this macro will cause a compilation error. For any other value of vt, use PROP_ENTRY_TYPE.
If you are creating a web control that needs to be initialized, you should use the IPersistPropertyBagImpl Class instead of IPersistStreamInitImpl to initialize properties. IPersistStreamInitImpl possess a greater risk in binary format than IPersistPropertyBagImpl.