From ReactOS

Windows XP version of ITEM and MENU

typedef struct _ITEM
{
/* 000 */ UINT          fType;
/* 004 */ UINT          fState;
/* 008 */ UINT          wID;
/* 00c */ struct _MENU *spSubMenu;
/* 010 */ HBITMAP       hbmpChecked;
/* 014 */ HBITMAP       hbmpUnchecked;
/* 018 */ LPWSTR        lpstr;
/* 01c */ UINT          cch;
/* 020 */ ULONG_PTR     dwItemData;
/* 024 */ DWORD         xItem;
/* 028 */ DWORD         yItem;
/* 02c */ DWORD         cxItem;
/* 030 */ DWORD         cyItem;
/* 034 */ DWORD         dxTab;
/* 038 */ DWORD         ulX;
/* 03c */ DWORD         ulWidth;
/* 040 */ HBITMAP       hbmp;
/* 044 */ DWORD         cxBmp;
/* 048 */ DWORD         cyBmp;
} ITEM, *PITEM;

/* Menu Item fType. */
#define MFT_RTOL        0x6000

typedef struct tagMENULIST
{
   struct tagMENULIST*  pNext;
   struct tagMENU*      pMenu;
} MENULIST, *PMENULIST;

// Menu fFlags, upper byte is MNS_X style flags.
#define MNF_POPUP       0x0001 // CreatePopupMenu->InternalCreateMenu(true);
#define MNF_UNDERLINE   0x0004 // if not underlined is ODS_NOACCEL, menustate.fUnderline
#define MNF_INACTIVE    0x0010 // Associated with ODS_INACTIVE
#define MNF_RTOL        0x0020
#define MNF_DESKTOPMN   0x0040 // LockDesktopMenu
#define MNF_SYSDESKMN   0x0080 // xxxLoadSysDesktopMenu
#define MNF_SYSSUBMENU  0x0100 // xxxGetSystemMenu for GetSubMenu

typedef struc _MENU
{
/* 000 */ PROCDESKHEAD  head;
/* 014 */ ULONG         fFlags;  // See menuinfo dwStyle.
/* 018 */ INT           iItem;
/* 01c */ DWORD         cAlloced;
/* 020 */ DWORD         cItems;
/* 024 */ DWORD         cxMenu;
/* 028 */ DWORD         cyMenu;
/* 02c */ DWORD         cxTextAlign;
/* 030 */ PWND          spwndNotify;
/* 034 */ PITEM         rgItems;
/* 038 */ PMENULIST     pParentMenus; // See Note 1.
/* 03c */ DWORD         dwContextHelpId;
/* 040 */ UINT          cyMax;
/* 044 */ ULONG_PTR     dwMenuData;
/* 048 */ HBRUSH        hbrBack;
/* 04c */ INT           iTop;
/* 050 */ INT           iMaxTop;
/* 054 */ DWORD         dwArrowsOn:2; //Arrows: 0 off, 1 on, 2 to the top, 3 to the bottom.
} MENU, *PMENU;

NOTE:

1. Pointer to a linked list of parent menu pointers. Allocated by DesktopAlloc with a size of 8 in xxxSetLPITEMInfo.

References

• msdn MENUINFO
• msdn MENUITEMINFO
• "Undocumented Windows, A Programmer's Guide to Reserved MS Win API Functions", page 473 - 477.
• Windows Symbol files, userkdx.dll, !dso, w7u