The AppGroupCreateAssoc request has the following possible variations: AppGroupCreateAssoc (X11) 1 CARD8 opcode 1 6 XC-APPGROUP opcode 2 n length 4 WINDOW window 2 0 window_type 2 4 system_window_len 4 WINDOW Window AppGroupCreateAssoc (Macintosh) 1 CARD8 opcode 1 6 XC-APPGROUP opcode 2 n length 4 WINDOW window 2 1 window_type 2 12 system_window_len 4 CARD32 WindowPtr 2 INT16 Rect.top 2 INT16 Rect.left 2 INT16 Rect.bottom 2 INT16 Rect.right AppGroupCreateAssoc (Win32) 1 CARD8 opcode 1 6 XC-APPGROUP opcode 2 n length 4 WINDOW window 2 2 window_type 2 4 system_window_len 4 CARD32 HWND AppGroupCreateAssoc (Win16) 1 CARD8 opcode 1 6 XC-APPGROUP opcode 2 n length 4 WINDOW window 2 3 window_type 2 4 system_window_len 2 CARD16 HWND offset 2 CARD16 HWND segment