Using Cross-References
  You may see cross-references within the text to other sec-
  tions. These cross-references to other sections are called
  hotspots. When you point to a hotspot, a rectangle surrounds
  it; when you double click MB1 on the hotspot, the cross-
  referenced section replaces the current section in the Topic
  window. Footnotes in text are also hotspots.

  If you want to view the cross-referenced section in a sep-
  arate Topic window, place the pointer over the hotspot and
  press MB3. Then choose Open Topic in New Window from
  the pop-up menu.

  By default, hotspots are highlighted only when you point to
  them. To highlight hotspots continuously, choose Hotspots
  from the Topic window's View menu. A shaded check button
  to the left of the Hotspot menu item indicates that continuous
  highlighting of hotspots is enabled.