+<p> <dfn>Crossfades</dfn> refer to the behavior when you want to make
+a smooth transition (mix) from one audio region to another on the same
+track. Historically, this was done by splicing 2 pieces of analog
+tape together, and this concept was carried forward into digital
+editing. Each track is a sequence of sound files (regions). If
+two regions are butted against each other, there needs to be a method
+to splice them smoothly together. The crossfade allows one region
+to fade smoothly out, while the next region fades smoothly in, like 2
+pieces of tape that have been cut at and angle, and overlapped.<br>
+</p>
+<p>But Ardour uses a more refined "layered" editing model, and
+therefore it is possible for multiple regions to be stacked on a single
+location with arbitrary overlaps between different layers. For
+this reason, crossfades must be implemented differently. We can't
+assume that a crossfade is an entitry that exists between 2 regions;
+instead each region must have its own associated crossfades at each
+end, and the topmost region must always crossfade down to the
+underlying region(s), if any.<br>
+</p>
+<p>Ardour solves this problem by putting a crossfade at the beginning
+and end of every region. The fades of the bottom-most region are
+first rendered, and then each region is rendered on top of the one
+below it, with fades at the end of each region providing a crossfade to
+the region(s) beneath it. <br>
+</p>
+<p>It is important to understand that region fades <em>are</em> crossfades. When one region has
+another region or multiple regions beneath its fade area, then you will
+hear the topmost region fade-out be mirrored as a fade-in on the
+underlying region(s). The grip for the topmost region will allow
+changing the length and type of the crossfade into the underlying
+region(s). In this way you can create a complicated series of
+crossfades, and then layer another region atop the others, and fade
+into _that_ complicated series. <em>An image here would
+probably help.</em><br>
+</p>
+<p>If a region doesn't have any region(s) under it, then the region is
+crossfaded to silence; for convenience we call this a "fade"
+rather than a crossfade.<br>
+</p>
+<h2>Fade Shapes<br>
+</h2>
+<p>To activate/deactivate or change the shape of a region's fadein or
+fade-out, hover the cursor over the regionfade grip till the cursor tip
+indicates region fade editing and context-click to bring up a context
+menu. In the context menu there is a list of options for the
+regionfade. <kbd class="menu">Activate/Deactivate</kbd> enables and
+disables the regionfade.<br>
+</p>
+<p>Because each fade is also a crossfade, it has an inverse fade shape
+for the audio beneath the fade. It is important to know how the
+shapes differ, and which are most suitable for various editing tasks.<br>
+</p>
+<p>The different types of fades are:<br>