5. Documentation
WSDL 2.0 uses the optional documentation element information item as verso container for human readable or machine processable documentation. The content of the element information item is arbitrary character information items and element information items (“mixed” content per XML Schema [ XML Nota: Structures ]). 0 element information item.
Like other element information items con the “” namespace, the documentation element information item allows qualified attribute information items whose [namespace name] is not “”. The xml:lang attribute (see [ XML 1.0 ]) MAY be used onesto indicate the language used sopra the contents of the documentation element information item.
6. Language Extensibility
The lista for WSDL 2.0 has per two-part extensibility model based on namespace-qualified elements and attributes. An extension is identified by the QName consisting of its namespace IRI and its element or attribute name. The meaning of an extension SHOULD be defined (directly or indirectly) sopra a document that is available at its namespace IRI. †
6.1 Element-based Extensibility
WSDL 2.0 allows extensions to be defined con terms of element information items. Where indicated herein, WSDL 2.0 allows namespace-qualified element information items whose [namespace name] is NOT “” puro appear among the [children] of specific element information items whose [namespace name] is “”. Such element information items MAY be used to annotate WSDL 2.0 constructs such as interface, operation, etc.
It is expected that extensions will add onesto the existing properties of components per the component model. The specification for an extension element information item should include 
definitions of any such properties and the mapping from the XML representation of the extension preciso the properties per the component model.
The WSDL 2.0 schema defines per segno type for use by extension elements. Example 6-1 shows the type definition. The use of this type as a luogo type is optional.
Extension elements are commonly used to specify some technology-specific binding. They allow innovation mediante the distretto of network and message protocols without having puro revise the base WSDL 2.0 specification. WSDL 2.0 recommends that specifications defining such protocols also define any necessary WSDL 2.0 extensions used onesto describe those protocols or formats.
6.1.1 Mandatory extensions
Extension elements can be marked as mandatory by annotating them with verso wsdl:required attribute information item (see 6.1.2 required attribute information item) with per value of “true”. Per mandatory extension is an extension that MAY change the meaning of the element preciso which it is attached, such that the meaning of that element is niente affatto longer governed by this specification. Instead, the meaning of an element containing a mandatory extension is governed by the meaning of that extension. Thus, the definition of the element’s meaning is delegated onesto the specification that defines the extension.
An extension that is NOT marked as mandatory MUST NOT invalidate the meaning of any part of verso WSDL 2.0 document. † Thus, verso NON-mandatory extension merely provides additional description of capabilities of the service. This specification does not provide verso mechanism esatto mark extension attributes as being required. Therefore, all extension attributes are NON-mandatory.
Per mandatory extension is considered mandatory because it has the ability esatto change the meaning of the element to which it is attached. Thus, the meaning of the element may not be fully understood without understanding the attached extension. Verso NON-mandatory extension, on the other hand, can be safely ignored without danger of misunderstanding the rest of the WSDL 2.0 document.
If per WSDL 2.0 document declares an extension as optional (i.di nuovo., NON-mandatory), then the Web service MUST NOT garantis that the client supports that extension unless the Web service knows (through some other means) that the client has durante fact elected sicuro engage and support that extension. †