CCTS vs UDT

[ericdes <eric@vcardprocessor.com>]

Hi Ken,

Thank you for your previous answer. Now I would like to understand the 
differences between the "CCTS Core Component Type Schema Module" and  
the "UDT Unqualified Data Type Schema Module".

Why is e.g. "AmountType" defined in both those namespaces? Moreover it 
may have 2 optional attibutes "currencyID" and 
"currencyCodeListVersionID" in CCTS, while it may contain only one 
attribute, a required "currencyID" in UDT?

Thank you,
Eric.