Netscape Layout Extensions - HTML and XHTML: The Definitive Guide - page 1130

<layer>
<layer name=text left=0 top=0>
<h1>Introduction to Kumquat Lore</h1>
</layer>
<layer name=shadow above=text left=2 top=2>
<h1><font color=gray>Introduction to Kumquat Lore</font></h1>
</layer>
</layer>
The above attribute in the layer named shadow tells Netscape 4 to position
the shadow layer so that the layer named text is above it. The effect is
identical to Figure H-9 .
The above and below attributes can get confusing when you stack several
layers. We find it somewhat easier to use the z-index attribute for keep-
ing track of which layers go over which. With z-index , you specify the
order in which Netscape stacks the layers: higher z-index value layers
are put on top of lower z-index value layers.
For example, to create our drop shadow using the z-index attribute, we
would use the following:
<layer>
<layer left=0 top=0 z-index=2>
<h1>Introduction to Kumquat Lore</h1>
</layer>
<layer left=2 top=2 z-index=1>
<h1><font color=gray>Introduction to Kumquat Lore</font></h1>
</layer>
</layer>
Again, the effect is identical to Figure H-9 . Normally, Netscape 4 would
display the second layerthe gray one in this caseon top of the first layer.
But because we've given the gray layer a lower z-index value, it is
placed behind the first layer.