This element can be used in different contexts:

1. As an attributeGroup definition within xs:schema:

   Purpose	In this context, this element defines named groups of attributes. These attributes can subsequently be referenced in a complex type definition by a common name. See section 3.6 Attribute Group Definitions of XML Schema - Part 1.
   Parent element	xs:complexType, xs:extension, xs:schema
   Child elements	xs:attribute
   Attributes	name

   Attributes

   Name	Type	Description
   name	xs:NCName	The value of the name attribute specifies the name that identifies the group of attributes.

2. As an attributeGroup reference within xs:complexType or xs:attributeGroup or xs:extension:

   Purpose	This element references a predefined group of attributes. This leads to the insertion of the whole attribute group at the current location in the schema.
   Parent element	xs:complexType
   Child elements	xs:annotation (optional)
   Attributes	ref

   Attributes

   Name	Type	Description
   ref	xs:QName	A global attribute can be referenced in other declarations in the same schema using the ref attribute of the xs:attribute element. The value of the ref attribute must refer to a global element. If you specify a ref attribute, you may not specify a name attribute on that element declaration. Note: An attributeGroup reference can be nested within an attributeGroup definition. However, cyclic references are prohibited.