This appendix contains XML reference material. It is
divided into three main parts:
1. XML BNF Grammar
2. Well-Formedness Constraints
3. Validity Constraints
The XML BNF grammar reference section shows you how to
read a BNF Grammar and includes the BNF rules for XML 1.0
and examples of the XML 1.0 productions. The wellformedness
constraints reference section explains what a
well-formedness constraint is and lists the productions
associated with the well-formedness constraints. The validity
constraints reference section explains what a validity
constraint is and lists and explains all of the validity
constraints in the XML 1.0 Standard.
XML BNF Grammar
According to the XML 1.0 specification, an XML document is
well-formed if:
1. Taken as a whole it matches the production labeled
document.
2. It meets all the well-formedness constraints given in this
specification.
3. Each of the parsed entities which is referenced directly
or indirectly within the document is well-formed.
This section is designed to help you understand the first of
those requirements and more quickly determine whether your
documents meet that requirement.