Attributes are declared in an XML Schema using an <attribute> element, which has a number of attributes itself. Those attributes are used to place constraints on the properties of the attribute declaration.
The scope of an attribute declaration is determined by its placement within the XML Schema. To declare a global attribute, you would declare the attribute as a child of the <schema> element:
<xs:schema> <xs:attribute name="myAttribute"/> <xs:element name="someElement type="xs:string"/> </xs:schema>
In this example, the myAttribute attribute would be declared globally, because it is the child of the <schema> element, and not an element declaration. This means that the attribute could be referenced by ...