Editing : Fades and Crossfades : About Crossfades and Curves : Post Crossfade

Post Crossfade
This type of selection creates a crossfade after the splice point. It is useful if you want to maintain the amplitude of clip 1 until its very end. When making selections for crossfades that occur on the border of two clips, you can use the Tab key to move the cursor to the exact beginning or end of a clip.
This crossfade type requires that clip 1 contain audio material beyond its end point.