Pointer to the current plug-in instance. The plug-in information the call is setting. For values, see NPP_GetValue. Destination for plug-in information returned by the function.
If unsuccessful, the plug-in is not loaded and the function returns an error code. For possible values, see Error Codes.
For example, to specify that a plug-in is windowless, use NPP_SetValue with NPPVpluginWindowBool as the variable to set and false as the value parameter. If a plug-in does not make this call, it is considered a windowed plug-in.