In the list, all fields of the main list, the abstract and the HTML are shown - line by-line. With the checkbox in the column "List", one controls whether this value should be in the main list, or not. The column "Abstract" controls the output in the abstract in the same way. And the column "HTML" is responsible for the output into HTML files. Not all values (History, Spare parts and Live Cycle) can be used in the main list. Because of that, there is no checkbox for these values in the column "List".
With the two arrow keys on the right side one changes the order of the fields in the main list, abstract and HTML output. To change the order, you must select the line, first. By pressing an arrow key, the field moves a line higher or deeper. The abstract contains all fields of all lists (History, Spare parts and Live Cycle), but the elements can't be mixed. So you can move a field only within one list.