Questão Hard:
Compound types
SOAP defines types corresponding to the following structural patterns often found in programming languages:
Struct
A "struct" is a compound value in which accessor name is the only distinction among member values, and no accessor has the same name as any other.
Array
An "array" is a compound value in which ordinal position serves as the only distinction among member values.
SOAP also permits serialization of data that is neither a Struct nor an Array, for example data such as is found in a Directed-Labeled-Graph Data Model in which a single node has many distinct accessors, some of which occur more than once. SOAP serialization does not require that the underlying data model make an ordering distinction among accessors, but if such an order exists, the accessors MUST be encoded in that sequence.
FONTE: https://www.w3.org/TR/2000/NOTE-SOAP-20000508/#_Toc478383519