xsd:untypedAtomic

The generic xsd:untypedAtomic type is used in XPath 2.0, applying to all attribute nodes and atomic values that are "untyped", i.e., have no specific type. An attribute node is untyped if it was not validated against a schema declaration.

An atomic value might have the type xsd:untypedAtomic if it was extracted from an untyped element or attribute. Untyped atomic values can often be used wherever a typed value would. This is because every function and expression has rules for casting untyped values to an appropriate type.