I'm using GUI text editor SciTE and I want to use the following key combinations for selecting rectangular regions of text in SciTE: AltShiftUp and AltShiftDown.  It appears that I can do it in Linux Mint, but I can not get it to work in Debian.Debian blocks these keys.I want to know how to make these keys available for user applications.  My systems:Linux Mint 18, MATE 1.14.1  Debian 8.7 (jessie), MATE 1.8.1I use AltShift for switching keyboard layout (English-Russian) on both my systems.And I'd like it to stay that way (because of my finger memory).What I have tried:I opened dconf-editor and changed everywhere mouse-button-modifier from <Alt> to <Super>, and disabled all key combinations at all, then restarted Linux.That did not solve my problem.  Interesting detail:When I use VirtualBox (host = Debian, guest = Linux Mint), Alt-Shift-Up/Down key combinations work inside guest system!xev output for AltShiftUp on Linux Mint:  KeyPress event, serial 38, synthetic NO, window 0x3c00001,    root 0x26b, subw 0x3c00002, time 1272551, (42,42), root:(465,335),    state 0x10, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,    XLookupString gives 0 bytes:     XmbLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyPress event, serial 38, synthetic NO, window 0x3c00001,    root 0x26b, subw 0x3c00002, time 1273025, (42,42), root:(465,335),    state 0x18, keycode 50 (keysym 0xfe08, ISO_Next_Group), same_screen YES,    XLookupString gives 0 bytes:     XmbLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyPress event, serial 38, synthetic NO, window 0x3c00001,    root 0x26b, subw 0x3c00002, time 1273538, (42,42), root:(465,335),    state 0x19, keycode 111 (keysym 0xff52, Up), same_screen YES,    XLookupString gives 0 bytes:     XmbLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyRelease event, serial 38, synthetic NO, window 0x3c00001,    root 0x26b, subw 0x3c00002, time 1273605, (42,42), root:(465,335),    state 0x19, keycode 111 (keysym 0xff52, Up), same_screen YES,    XLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyRelease event, serial 38, synthetic NO, window 0x3c00001,    root 0x26b, subw 0x3c00002, time 1274384, (42,42), root:(465,335),    state 0x19, keycode 50 (keysym 0xfe08, ISO_Next_Group), same_screen YES,    XLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyRelease event, serial 38, synthetic NO, window 0x3c00001,    root 0x26b, subw 0x3c00002, time 1274824, (42,42), root:(465,335),    state 0x18, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,    XLookupString gives 0 bytes:     XFilterEvent returns: Falsexev output for AltShiftUp on Debian:  KeyPress event, serial 38, synthetic NO, window 0x4000001,    root 0x296, subw 0x4000002, time 13862445, (48,45), root:(85,108),    state 0x10, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,    XLookupString gives 0 bytes:     XmbLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyPress event, serial 38, synthetic NO, window 0x4000001,    root 0x296, subw 0x4000002, time 13862855, (48,45), root:(85,108),    state 0x18, keycode 50 (keysym 0xfe08, ISO_Next_Group), same_screen YES,    XLookupString gives 0 bytes:     XmbLookupString gives 0 bytes:     XFilterEvent returns: FalsePropertyNotify event, serial 38, synthetic NO, window 0x4000001,    atom 0x1c0 (XKLAVIER_STATE), time 13862856, state PropertyNewValuePropertyNotify event, serial 38, synthetic NO, window 0x4000001,    atom 0x1c0 (XKLAVIER_STATE), time 13862857, state PropertyNewValuePropertyNotify event, serial 38, synthetic NO, window 0x4000001,    atom 0x1c0 (XKLAVIER_STATE), time 13862857, state PropertyNewValuePropertyNotify event, serial 38, synthetic NO, window 0x4000001,    atom 0x1c0 (XKLAVIER_STATE), time 13862858, state PropertyNewValueKeyPress event, serial 38, synthetic NO, window 0x4000001,    root 0x296, subw 0x4000002, time 13863422, (48,45), root:(85,108),    state 0x2018, keycode 111 (keysym 0xff52, Up), same_screen YES,    XLookupString gives 0 bytes:     XmbLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyRelease event, serial 38, synthetic NO, window 0x4000001,    root 0x296, subw 0x4000002, time 13863489, (48,45), root:(85,108),    state 0x2018, keycode 111 (keysym 0xff52, Up), same_screen YES,    XLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyRelease event, serial 38, synthetic NO, window 0x4000001,    root 0x296, subw 0x4000002, time 13864456, (48,45), root:(85,108),    state 0x2018, keycode 50 (keysym 0xfe08, ISO_Next_Group), same_screen YES,    XLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyRelease event, serial 38, synthetic NO, window 0x4000001,    root 0x296, subw 0x4000002, time 13864793, (48,45), root:(85,108),    state 0x2018, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,    XLookupString gives 0 bytes:     XFilterEvent returns: Falsexev output for AltShift on Linux Mint:  KeyPress event, serial 38, synthetic NO, window 0x3c00001,    root 0x26b, subw 0x3c00002, time 3118153, (47,39), root:(78,133),    state 0x10, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,    XLookupString gives 0 bytes:     XmbLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyPress event, serial 38, synthetic NO, window 0x3c00001,    root 0x26b, subw 0x3c00002, time 3118245, (47,39), root:(78,133),    state 0x18, keycode 50 (keysym 0xfe08, ISO_Next_Group), same_screen YES,    XLookupString gives 0 bytes:     XmbLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyRelease event, serial 38, synthetic NO, window 0x3c00001,    root 0x26b, subw 0x3c00002, time 3118377, (47,39), root:(78,133),    state 0x19, keycode 50 (keysym 0xfe08, ISO_Next_Group), same_screen YES,    XLookupString gives 0 bytes:     XFilterEvent returns: FalsePropertyNotify event, serial 38, synthetic NO, window 0x3c00001,    atom 0x1c4 (XKLAVIER_STATE), time 3118380, state PropertyNewValuePropertyNotify event, serial 38, synthetic NO, window 0x3c00001,    atom 0x1c4 (XKLAVIER_STATE), time 3118382, state PropertyNewValuePropertyNotify event, serial 38, synthetic NO, window 0x3c00001,    atom 0x1c4 (XKLAVIER_STATE), time 3118383, state PropertyNewValuePropertyNotify event, serial 38, synthetic NO, window 0x3c00001,    atom 0x1c4 (XKLAVIER_STATE), time 3118385, state PropertyNewValueKeyRelease event, serial 38, synthetic NO, window 0x3c00001,    root 0x26b, subw 0x3c00002, time 3118535, (47,39), root:(78,133),    state 0x2018, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,    XLookupString gives 0 bytes:     XFilterEvent returns: Falsexev output for AltShift on Debian:  KeyPress event, serial 38, synthetic NO, window 0x4000001,    root 0x296, subw 0x4000002, time 16284126, (36,50), root:(76,134),    state 0x10, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,    XLookupString gives 0 bytes:     XmbLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyPress event, serial 38, synthetic NO, window 0x4000001,    root 0x296, subw 0x4000002, time 16284503, (36,50), root:(76,134),    state 0x18, keycode 50 (keysym 0xfe08, ISO_Next_Group), same_screen YES,    XLookupString gives 0 bytes:     XmbLookupString gives 0 bytes:     XFilterEvent returns: FalsePropertyNotify event, serial 38, synthetic NO, window 0x4000001,    atom 0x1c0 (XKLAVIER_STATE), time 16284506, state PropertyNewValuePropertyNotify event, serial 38, synthetic NO, window 0x4000001,    atom 0x1c0 (XKLAVIER_STATE), time 16284506, state PropertyNewValuePropertyNotify event, serial 38, synthetic NO, window 0x4000001,    atom 0x1c0 (XKLAVIER_STATE), time 16284507, state PropertyNewValuePropertyNotify event, serial 38, synthetic NO, window 0x4000001,    atom 0x1c0 (XKLAVIER_STATE), time 16284507, state PropertyNewValueKeyRelease event, serial 38, synthetic NO, window 0x4000001,    root 0x296, subw 0x4000002, time 16284786, (36,50), root:(76,134),    state 0x2018, keycode 50 (keysym 0xfe08, ISO_Next_Group), same_screen YES,    XLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyRelease event, serial 38, synthetic NO, window 0x4000001,    root 0x296, subw 0x4000002, time 16285071, (36,50), root:(76,134),    state 0x2018, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,    XLookupString gives 0 bytes:     XFilterEvent returns: FalseAs you can see, AltShift key combination is processed differently:on Debian keyboard layout is switched on key PRESS,  on Linux Mint keyboard layout is switched on key RELEASE.Sequence:ALT pressedSHIFT pressed(at this moment Debian switches layout)SHIFT released(at this moment Linux Mint switches layout)ALT releasedProbably, this is the reason why AltShiftUp does not work on Debian.  How can I make AltShiftUp coexist with AltShift on Debian?
Some key combinations are not available for user applications
keyboard shortcuts;mate