The XML Schema API
specification defines a set of interfaces for accessing and querying the post schema
validation infoset (PSVI) defined in
to the post-schema-validation infoset (Appendix C.2). These interfaces
provide access to the XML Schema components, which follow as a consequence of
validation and/or assessment and also provide a means for accessing the PSVI
from a document instance.
Some of the interfaces in the XML Schema API reference interfaces
from DOM Level 3
which is now a W3C Recommendation.