4

this applies to list / column / other vertical views in dolphin and all other lists that allow multiple item selection

on the view (near the file sizes) there is a thin strip lightly shaded in color. clicking or dragging on it allows smart selection of items

for example
green strip - everything you click or drag over is selected. if its allready selected nothing happens. if there is allready selection and you click or drag more than the selection is added (without need to hold ctrl)
gray strip - unselects stuff (opposite to green)
blue strip - acts as green if drag started on unselected item. acts as grey if on selected item
yellow strip - xors stuff
clear strip - acts like white space now

by default only the blue strip is visible as thin strip on the edge of the file size column (partially covering the numbers but its allmost transparent). everything else is clear

inspired by the full row select option thread