DOCBOOK: Purpose of <screen> in slides.dtd?

[Christoph Steinbeck <steinbeck@ice.mpg.de>]

Can anyone tell me the purpose of <screen> in slides.dtd?
As I understand, <slide> gives my single html page with the regular html
xslt stylesheet, so what would <screen> be good for?

Cheers, 

Chris

--
Dr. Christoph Steinbeck (http://www.ice.mpg.de/departments/ChemInf)
MPI of Chemical Ecology, Carl-Zeiss-Promenade 10, 07745 Jena, Germany
Tel: +49(0)3641 643644 - Fax: +49(0)3641 643665

What is man but that lofty spirit - that sense of enterprise. 
... Kirk, "I, Mudd," stardate 4513.3..