As kps explained, in WASD, the counting starts at the bottom (ctrl row and shift-zxcv rows are considered row 1, capslock row as row 2, tab row as row 3, and tilde/esc rows as row 4). Be careful, though, because in other systems the counting starts from the top (esc/tilde row are considered row 1, tab row as 2, capslock row as 3, and the bottom two rows as row 4). The terminology for modifier (shift, ctrl, alt, etc) key sizes should be the same, as far as I know.