Thanks, works now like this
[hotkey]
pause = P ; Pause/unpause game
[hotkey.camera]
rotate.wheel.cw = "Shift+WheelUp" ; Rotate camera clockwise around terrain (stepped control)
rotate.wheel.ccw = "Shift+WheelDown" ; Rotate camera anticlockwise around terrain (stepped control)
[hotkey.selection]
idleworker = Period, MouseX2 ; Select next idle worker
[hotkey.session]
stop = "H", MouseX1 ; Stop the current action
It's pretty confusing as default.cfg says
But anyway thanks a lot.