Sustainability of Digital Formats
Planning for Library of Congress Collections
Sustainability of Digital Formats
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| Introduction | Sustainability Factors | Content Categories | Format Descriptions | Contact | |
| Full name | Extensible Markup Language (XML) 1.0 |
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| Description | Extensible Markup Language (XML) is a simple, very flexible text format derived from SGML (ISO 8879). See XML. Version 1.0 is a W3C Recommendation. As of March 2008, XML 1.0 is based on Unicode, Version 2. |
| Production phase | Can be used as initial, middle, or final-state format. |
| Relationship to other formats | |
| Has later version | XML_1_1, XML (Extensible Markup Language) 1.1 |
| Subtype of | XML, Extensible Markup Language |
| Contains | Unicode, Version 2. Not described here. See Unicode 2.0.0 (July, 1996). |
| LC experience or existing holdings | See XML. |
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| LC preference | See XML. |
| Disclosure | Open standard. Developed by W3C (World Wide Web Consortium). See XML. |
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| Documentation | Maintained by W3C [http://www.w3.org/XML/]. As of March 2008, the latest edition is Extensible Markup Language (XML) 1.0 (Fourth Edition). See Notes below. |
| Adoption | See XML. |
| Licensing and patents | None |
| Transparency | See XML. |
| Self-documentation | See XML. |
| External dependencies | None |
| Technical protection considerations | None |
| Text | |
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| Normal rendering | See XML. |
| Integrity of document structure | See XML. |
| Integrity of layout and display | See XML. |
| Support for mathematics, formulae, etc. | See XML. |
| Functionality beyond normal rendering | See XML. |
| Tag | Value | Note |
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| Filename extension | xml |
Common practice for XML document instances is to use the .xml extension. The particular schema or DTD should be declared within the document. Some schemas specify the use of different file extensions. |
| General | |
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| History | Several editions of the XML 1.0 specification have been published as W3C Recommendations. The underlying specification has not changed. The first edition of XML 1.0 became a W3C recommendation in February 1998. See http://www.w3.org/Press/1998/XML10-REC. The second edition, released in October 2000, incorporated the changes dictated by the first-edition errata. The third edition was released in February 2004. This integrated changes dictated by errata and also introduced markup on a significant portion of the prescriptions of the specification, clarifying when prescriptive keywords such as MUST, SHOULD and MAY are used in the formal sense defined in IETF RFC 2119. In the fourth edition, released in August 2006, this markup was modified to better match the intent of IETF RFC 2119 and to integrate changes dictated by errata. XML 1.1, originally released in February 2004, updated XML 1.0 so that it no longer depends on a specific Unicode version: the latest version can always be used. It also adds checking of normalization, and follows the Unicode line ending rules more closely. Authors are encouraged to generate XML 1.0 documents if the added flexibility is not required. XML Parsers are expected to understand both XML 1.0 and XML 1.1. |
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