doubts in XML Schemas

[PJ]

Hi,


I have an sample of XML Schema it has


(I)<xs:element ref=ABC"/>
(II)<xs:element name="XYZ" type="mno" minOccur="0"/>


I want to ask:
(1)What is the difference between (I) and (II) (ref,name)
(2)Does (I) means the occurance of this element should be mandatory
(and only one times)
(3)Does (II) means that this element is Optional.


And how do we make it out that the occurance os sub element in the main

element is should be in specific order.


thanks
PJ

 

[Martin Honnen]

I have an sample of XML Schema it has


(I)<xs:element ref=ABC"/>
(II)<xs:element name="XYZ" type="mno" minOccur="0"/>


I want to ask:
(1)What is the difference between (I) and (II) (ref,name)

With
<xsl:element name="XYZ" />
an element is defined.
With
<xsl:element ref="ABC" />
an element is referenced that has to be defined elsewhere.