There are several methods for selecting and deselecting entries.

Select a single entryIn Titles or List View mode, click anywhere on the entry except on the Expand/Collapse arrow and on Sort buttons of parent entries.

In Proxies mode, click anywhere on the proxy except in the jogging area or on the Play button.

In Titles and List View mode, a selected entry is light grey. On proxies, the name bar is yellow. When you click a parent entry, the parent entry and all its child entries are selected.

When a parent entry contains some selected child entries, but not all of them, its Expand or Collapse arrow is yellow. When all of a parent entry's child entries are selected, its Expand or Collapse arrow is green.

Select all child entries of a parent entryClick the parent entry.

Add more entries to a selection Ctrl-click (or use the pen button) each entry you want to add.

Deselect one or more entries Ctrl-click each entry (or use the pen button).

Select a range of entriesClick the first entry in the range, then press Shift and click the last entry in the range. In List View, you can also drag the cursor over the range of entries.

Add a range of entries Ctrl-click the first entry in the range you want to add to your current selection. Shift-click the last entry in the range you want to add.

Select all entries in the clip libraryClick the Select All button in the Library Management menu. Alternatively, click the clip library entry.

Deselect all entriesClick the Unselect All button in the Library Management menu. Alternatively, Ctrl-click (or use the pen button) anywhere in the solid grey area of the clip library.