<H2><A NAME=epsf>User-defined Nodes</A></H2>

There is a third type of node shape which is specified by the user.
Typically, these shapes rely on the details of a concrete graphics
format. At present, shapes can be described using PostScript, via a
file or add-on library, for use in PostScript output, or shapes can
be specified by a bitmap-image file for use with SVG or bitmap (jpeg,
gif, etc.) output. More information can be found on the page 
<A HREF="http://www.graphviz.org/wiki/how-create-custom-shapes">
How to create custom shapes</A>.

<H2><A NAME=sdlshapes>SDL Shapes for PostScript</A></H2>
One example of user-defined node shapes is provided by Mark Rison of CSR.
These are the <A  HREF=http://www.sdl-forum.org/SDL/index.htm>SDL</A> shapes.
These are available as PostScript functions whose use is described in
<A HREF="http://www.graphviz.org/Documentation/html/shapehowto.html#psprocs"> External PostScript procedures</A>.
The necessary PostScript library file and sample use can be found in the
<tt>contrib/sdlshapes</tt> directory in the release. Please note the
COPYRIGHT AND PERMISSION NOTICE contained in the library file <tt>sdl.ps</tt>.
<P>
The table below
gives the shape names and the corresponding node shapes.
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