The Tack Icon

The User Interface > Preview/Edit Window > Text/Edit Tab > Editor Toolbar... > The Tack Icon

A very useful mode of operation when doing extensive editing on a clip is to "tack" the editor to the clip.  Normally, each editor window will display the clip that is currently on the clipboard.  That's usually ok, but what if you want to cut and paste within a clip?  Or combine two clips?  Then you will need to "tack" the editor to the clip that you are working on.  Now you can cut/copy/paste, without the editor trying to display the current clipboard contents.