Here's an example of how to use the old openscreen() call with an
extnewscreen structure to make a new, custom screen under any version of
the Amiga operating system.  If the version is V36 or later, additional
Release 2 features specified via tags, in this case the new 3D look of
Intuition, will be incorporated in the window.

     screen34to37.c 

As you can see from the examples above, there are many ways to create a
new, custom screen.  further references to "openscreentaglist()" in this
manual are referring to any one of the three calls: OpenScreenTagList(),
openscreentags(), or openscreen() used with tags in an extnewscreen as
shown above.