manual/include/moving-markers.html

  
<h2>Single marker</h2>
<p>
  <kbd class="mouse">Left</kbd>-click and drag to move a single marker to a 
  new location on the timeline.
</p>

<h2>Multiple markers</h2>
<p>
  It is possible to move multiple markers by the same distance. <kbd
  class="mouse mod1">Left</kbd>-click each marker you want to move, then drag 
  one of the selected markers to a new location. All selected markers will
  then move together. Note that the markers are bounded by the zero point on 
  the timeline. In other words, the first marker in your selection cannot move 
  to the left of zero on the timeline.
</p>

<h2>Both ends of a range marker</h2>
<p>
  <kbd class="mod1 mouse">Left</kbd>-drag either end of the range marker. The 
  other end will move by the same distance.
</p>