Should WCF DataContracts be values ​​or reference types?

Question

You are at the end of the service and do not know your customers.

Why do you choose one of them?

Answer 1

Usually; when developing a type on its own, it must be a class, unless the type represents a single value, in which case it must be a structure.

Answer 2

. , , . XML- WSDL. , , Perl ASP- - , .

, vs. reference - , , .

Answer 3

, . WSDL, WCF, , . WCF , . , vs reference isNullable WSDL, .

, , - ( ) .