XML in a Nutshell, 3rd Edition

Name

xs:attributeGroup

Synopsis

<xs:attributeGroup
  id = "ID"
  name = "NCName"
  ref = "QName">
  <!--
    ( xs:annotation?, (xs:attribute | xs:attributeGroup)*,
      xs:anyAttribute? )
   -->
</xs:attributeGroup>

The xs:attributeGroup element is used in two ways. At the top level of the schema, it has a name attribute and defines a new attribute group. The attributes in the group are indicated by the child elements of the xs:attributeGroup element. Inside an xs:complexType element or another xs:attributeGroup, it has a ref attribute but no name and adds the attributes in the referenced group to the type or group’s list of attributes.