2.1.1 [W3C-XSS] Section 3.3.1, The Element Declaration Schema Component
V0001:
The specification states:
{value constraint} establishes a default or fixed value for an element. If
default is specified, and if the element being ·validated· is empty, then the
canonical form of the supplied constraint value becomes the [schema normalized
value] of the ·validated· element in the ·post-schema-validation infoset·. If
fixed is specified, then the element's content must either be empty, in which
case fixed behaves as default, or its value must match the supplied constraint
value.MSXML6
If an element that is being validated includes a {value constraint} value that is specified as default and the element is empty, the default value is not supplied.
