Minor changes in Section 4.4
From "Motivation elements are usually denoted using boxes with diagonal corners." to "Motivation elements are denoted using boxes with diagonal corners and an icon in the upper-right corner, or by the icon on its own."
From "Motivation elements are usually denoted using boxes with diagonal corners." to "Motivation elements are denoted using boxes with diagonal corners and an icon in the upper-right corner, or by the icon on its own."