World A9.2 Q on P430301

 When inquiring, same PO appears several times depending on number of lines....on some instances the PO # is highlighted and on others not.  I see the exit option is highighted and that indicates that there is associated text.On some though both the PO is highlighted and the Option isn't as there is no text.  What does it mean when the PO itself is highlighted for some lines but not others