Secure XML: The New Syntax for Signatures and Encryption

5.3. Elements and Attributes

An occurrence of xs:element specifies an element. It must have a “name” attribute or a “ref” attribute, but not both. If a “name” attribute appears, then a “type” attribute can appear. The value of a “type” attribute is the name of a type, either simple or complex; it specifies that the element will be of that type. The value of a “ref” attribute is the name of a global element; it indicates that the element being specified, presumably as part of a structure, has the same name and type as does the global element. In the absence of either a “type” or “ref” attribute, the element specification must contain an anonymous type (described later), or it will default to type “anyType” (also described later).

Schema elements ...