2.2.8
Defining Other Lists
You can use any other atomic simple type definition or built-in primitive
datatype in <xsd:list itemType="..."/>.
The XML representation would be a list of values of that type,
separated by white space. And right here is a potential catch: what if one of
these values contains a blank? Therefore, unless you can be very sure
that your strings are free from spaces or any other white space, don't
use anything like
<xsd:simpleType name="StringListType">
<xsd:list itemType="xsd:string"/> <!-- dangerous! -->
</xsd:simpleType>
To be on the safe side, use a complex type that contains a sequence of
string elements.