Press Ctrl+F9 on the keyboard to switch keyboard focus to the tree or list with the clips in the active collection. You can then navigate through the list with the keyboard. Press the arrow keys to move around the tree. Press the + (plus) and - (minus) keys to expand or collapse folders. Press Home or End to go to the first or last item in the collection. Keep the Shift key depressed while pressing the arrow keys to select multiple clips.
Pressing Ctrl+F9 does not change the visibility of the AceText Tower at any time. If the AceText Tower is hidden, the tree will be visible inside the AceText Editor. Ctrl+F9 focuses the tree wherever it is visible. Press Ctrl+F8 to show the AceText Tower.
Note that you can walk through the list of clips even when the tree does not have keyboard focus. Simply press Ctrl+Shift+Arrow Up or Ctrl+Shift+Arrow Down. One key difference is that the Ctrl key method will always walk through clips inside folders. Using the arrow keys without Ctrl when the tree has input focus, on the other hand, only selects clips inside folders when those folders have been expanded.