Originally discovered (as far as I know) by Paul McNett and mentioned in bug 1264, typing a shift-tab in an app under Wine generates the message: err:keyboard:X11DRV_ToUnicode Please report: no char for keysym FE20 (ISO_Left_Tab) : err:keyboard:X11DRV_ToUnicode (virtKey=9,scanCode=F,keycode=17,state=1) So here is a report.