ulReserved (ULONG)

Reserved value, should be 0.

ReturnCode contains ulReserved for a usnotifycode of MLN_OVERFLOW, MLN_HSCROLL, MLN_VSCROLL, MLN_CHANGE, MLN_UNDOOVERFLOW, MLN_CLPBDFAIL, MLN_MEMERROR, MLN_SETFOCUS, or MLN_KILLFOCUS.