An element information item conforms to this specification if it meets the structural requirements for include elements defined in this specification. This specification imposes no particular constraints on DTDs or XML schemas; conformance applies only to elements and attributes.
An application conforms to XInclude if it:
supports [XML 1.0] and [Namespaces in XML] or [XML 1.1] and [Namespaces in XML 1.1], the [XML Information Set], [XML Base], the [XPointer Framework], and the [XPointer element() scheme];
stops processing when a fatal error is encountered;
observes the mandatory conditions (must) set forth in this specification, and for any optional conditions (should and may) it chooses to observe, observes them in the way prescribed; and
performs markup conformance testing according to all the conformance constraints appearing in this specification.
Support for the [XPointer xpointer() Scheme] is not mandatory for full XInclude conformance. Authors are advised that use of xpointer() and other XPointer schemes than element() might not be supported by all conformant XInclude implementations.
This specification conforms to the [XML Information Set]. The following information items must be present in the input infosets to enable correct processing:
Document information items with children and base URI properties.
Element information items with namespace name, local name, children, attributes, base URI and parent properties.
Attribute information items with namespace name, local name and normalized value properties.
Additionally, XInclude processing might generate the following kinds of information items in the result:
Character information items with character code, element content whitespace and parent properties.
XInclude extends the infoset with the property include history, which may appear on the following types of information items in the result:
Element information items.
Processing instruction information items.
Comment information items.
Character information items.
XInclude also extends the infoset with the property language, which may appear on element information items in the result.