Validating data entry
This section describes the status of this document at the time of its publication. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at It has been reviewed by W3C Members and other interested parties, and has been endorsed by the Director as a W3C Recommendation.
It is a stable document and may be used as reference material or cited as a normative reference from another document.
Its goal is to enable generic SGML to be served, received, and processed on the Web in the way that is now possible with HTML.
XML has been designed for ease of implementation and for interoperability with both SGML and HTML.
XML was developed by an XML Working Group (originally known as the SGML Editorial Review Board) formed under the auspices of the World Wide Web Consortium (W3C) in 1996.
It was chaired by Jon Bosak of Sun Microsystems with the active participation of an XML Special Interest Group (previously known as the SGML Working Group) also organized by the W3C.
As explained in 2.11 End-of-Line Handling, all #x D characters literally present in an XML document are either removed or replaced by #x A characters before any other processing is done.
The only way to get a #x D character to match this production is to use a character reference in an entity value literal.
1 Introduction 1.1 Origin and Goals 1.2 Terminology 2 Documents 2.1 Well-Formed XML Documents 2.2 Characters 2.3 Common Syntactic Constructs 2.4 Character Data and Markup 2.5 Comments 2.6 Processing Instructions 2.7 CDATA Sections 2.8 Prolog and Document Type Declaration 2.9 Standalone Document Declaration 2.10 White Space Handling 2.11 End-of-Line Handling 2.12 Language Identification 3 Logical Structures 3.1 Start-Tags, End-Tags, and Empty-Element Tags 3.2 Element Type Declarations 3.2.1 Element Content 3.2.2 Mixed Content 3.3 Attribute-List Declarations 3.3.1 Attribute Types 3.3.2 Attribute Defaults 3.3.3 Attribute-Value Normalization 3.4 Conditional Sections 4 Physical Structures 4.1 Character and Entity References 4.2 Entity Declarations 4.2.1 Internal Entities 4.2.2 External Entities 4.3 Parsed Entities 4.3.1 The Text Declaration 4.3.2 Well-Formed Parsed Entities 4.3.3 Character Encoding in Entities 4.4 XML Processor Treatment of Entities and References 4.4.1 Not Recognized 4.4.2 Included 4.4.3 Included If Validating 4.4.4 Forbidden 4.4.5 Included in Literal 4.4.6 Notify 4.4.7 Bypassed 4.4.8 Included as PE 4.4.9 Error 4.5 Construction of Internal Entity Replacement Text 4.6 Predefined Entities 4.7 Notation Declarations 4.8 Document Entity 5 Conformance 5.1 Validating and Non-Validating Processors 5.2 Using XML Processors 6 Notation A References A.1 Normative References A.2 Other References B Character Classes C XML and SGML (Non-Normative) D Expansion of Entity and Character References (Non-Normative) E Deterministic Content Models (Non-Normative) F Autodetection of Character Encodings (Non-Normative) F.1 Detection Without External Encoding Information F.2 Priorities in the Presence of External Encoding Information G W3C XML Working Group (Non-Normative) H W3C XML Core Working Group (Non-Normative) I Production Notes (Non-Normative) Extensible Markup Language, abbreviated XML, describes a class of data objects called XML documents and partially describes the behavior of computer programs which process them.They are either control characters or permanently undefined Unicode characters: [#x7F-#x84], [#x86-#x9F], [#x FDD0-#x FDDF], [#1FFFE-#x1FFFF], [#2FFFE-#x2FFFF], [#3FFFE-#x3FFFF], [#4FFFE-#x4FFFF], [#5FFFE-#x5FFFF], [#6FFFE-#x6FFFF], [#7FFFE-#x7FFFF], [#8FFFE-#x8FFFF], [#9FFFE-#x9FFFF], [#AFFFE-#x AFFFF], [#BFFFE-#x BFFFF], [#CFFFE-#x CFFFF], [#DFFFE-#x DFFFF], [#EFFFE-#x EFFFF], [#FFFFE-#x FFFFF], [#10FFFE-#x10FFFF].Note: The presence of #x D in the above production is maintained purely for backward compatibility with the First Edition.This document specifies a syntax created by subsetting an existing, widely used international text processing standard (Standard Generalized Markup Language, ISO 8886(E) as amended and corrected) for use on the World Wide Web.It is a product of the XML Core Working Group as part of the XML Activity.
The English version of this specification is the only normative version. As a convenience to readers, it incorporates the changes dictated by the accumulated errata (available at to the Second Edition of XML 1.0, dated 6 October 2000.