built-in data type
Every element-declaration instance has a shelf of type attribute-declaration, which can be obtained with the syntax attributes of element-declaration. This shelf has the same number of items and is keyed the same way as the attributes shelf for the corresponding element event. For element events produced by a validating SGML or XML parse, this is the number of declared attributes for the element. In the case of a well-formed XML parse, this is the number of specified attributes.
Every attribute-declaration instance has two properties:
Considering that elements have attributes, one first has to create an attribute-declaration that corresponds to the attributes that an element should have, before one creates a new element-declaration.