Edit menu

The Edit menu commands are the following:

Undo (on the Windows system)
Cancels the previous Delete command.
Undo Delete (on Linux)
Cancels the previous Delete command.
Delete
Removes the selected item or all selected items from the merge. Click Edit > Undo (on the Windows system) or Undo Delete (on Linux) to cancel.
Select
Opens the Select window, which lets you select an element or elements from the list of elements to be merged based on a chosen criterion, for example, merge type.
Select All
Selects all elements currently listed.