The <anyAttribute> element enable us to extend the XML document with attributes not specified by the schema.

The following example is the fragment from an XML schema called "family.xsd". It shows a declaration for "person" element. By using the <anyAttribute> element we can add any number of attributes to "person" element:

Now we want to extend "person" element with a "gender" attribute. In this case we can do so, even if the author of the schema above never declared any "gender" attributes.

Look at this schema file, called "attribute.xsd":

The XML file below (called "Myfamily.xml"), uses component from two different schemas; "family.xsd" and "attribute.xsd":

The XML file above is valid because the schema "family.xsd" allow us to add an attribute to the "person" element.

The <any> and <anyAttribute> elements are used to make EXTENSIBLE document! They allow documents to contain additional elements that are not declared in the main XML schemas.