Shift three. Caps lock one. Shift six.
Tab six. Tab nine. Tab seven.
Tab four. Tab three. Caps lock one. Caps lock three.
Tab five. Caps lock six. Tab eight. Caps lock two. Shift 10.
It spells out “Can you read this?”
Use your keyboard like a grid. Tab, caps lock and shift are the vertical side of the grid and one through nine are the horizontal side of the grid. For example shift five would be B.