I didn't know about CCM_SETUNICODEFORMAT and WM_NOTIFYFORMAT, thanks for information (btw. MSDN says from IE5.0). But, could it be possible that KernelEx automatically uses one of those two methods for unicode apps? For example, app is unicode (made for NT family of windows) and uses unicode data in WM_NOTIFY, but author didn't know about existence of KernelEx and possibility that his app will be used on Win98 so he didn't implement CCM_SETUNICODEFORMAT or WM_NOTIFYFORMAT.