Table of contents

Appendices

2.1 Overview of XML Schema

An XML Schema consists of components such as type definitions and element declarations. These can be used to assess the validity of well-formed element and attribute information items (as defined in [ref-xmlinfo]), and furthermore may specify augmentations to those items and their descendants. This augmentation makes explicit information which may have been implicit in the original document, such as normalized and/or default values for attributes and elements and the types of element and attribute information items.

Schema-validity assessment has two aspects:

1. determining local schema-validity, that is whether an element or attribute information item satisfies the constraints embodied in the relevant components of an XML Schema;

2. Synthesizing an overall validation outcome for the item, combining local schema-validity with the results of schema-validity assessments of its descendants, if any, and adding appropriate augmentations to the infoset to record this outcome.

Throughout this specification, the word valid and its derivatives are used to refer to [c-lsv] above, the determination of local schema-validity.

Throughout this specification, the word assessment is used to refer to the overall process of local validation, schema-validity assessment and infoset augmentation.