If the document's schema is an XML Schema [XML Schema Part 1] , this constant represents the list.
The reference type definition is derived by list from the other type definition if there exists two type definitions T1 and T2 such as the reference type definition is derived from T1 by DERIVATION_RESTRICTION or DERIVATION_EXTENSION, T2 is derived from the other type definition by DERIVATION_RESTRICTION, T1 has {variety} list, and T2 is the {item type definition}. Note that T1 could be the same as the reference type definition, and T2 could be the same as the other type definition.