If when you select 'Show readers' there are results (relevant people have viewed the discussion) you see quite a bit of explanatory text above the table, telling you who might or might not appear in the list.

If you select 'Show readers' and there are no results (no relevant people have viewed the discussion) the only text displayed is 'Nothing to display'. It might be helpful if there was some sort of explanatory text displayed in the latter situation.

So we will change it so that the explanatory text is always displayed even when there are no readers, and the 'Nothing to display' message appears in a paragraph/box below the explanation and is changed to something slightly more meaningful such as:

So far, nobody who meets the above conditions has read this forum discussion.