Hallo Georg,
I found some information in my link collection which may help you additionally. Look at
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and download "Licensing Model for Windows CE Document" (Word-doc) for more information about this topic. It is quite good to find out what are the differences about Core and Professional Licence regarding to PB5's Catalog Items.
Also you can look at
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as an entry point for more information about AYGShell and a little of its "historical" background...