For questions on XML in general, please see the excellent XML FAQ maintained by Peter Flynn. You can also look at the Robin Cover's Pages, one of the best places to look for information about XML.

Last update of this FAQ: Sep-20-07.

Character Representation:

• What character can I use in an XML document?
• What is an NCR?
• Does 146 in ’ corresponds to Unicode or the document's encoding?
• Can I use character entity references like á in an XML document?
• How do I define a character entity?
• Can element and attribute names use non-ASCII characters?
• How do I represent extended characters in CSS?
• How do I represent extended characters in URIs (URNs/URLs)?

Encoding:

• What is the default encoding of an XML document?
• Which encodings XML parsers support?
• How do I specify the encoding of a document?
• How do I specify the encoding of a CSS file?
• What are UTF-8 and UTF-16?
• What is the BOM (Byte-Order-Mark)?
• How do I convert an XML document from one encoding to another?

Language Identification:

• What is the xml:lang attribute?
• Do I need to declare the xml:lang attribute?
• What are the values for the xml:lang attribute?
• In XHTML should I use lang or xml:lang?
• What about multilingual documents?
• Can I use Unicode Language Tags in XML?
• How do I use the lang() function in XPath?
• How do I use the lang() selector in CSS?

Presentation and Rendering:

• How do I render ruby text?
• How do I render bi-directional  text?
• How do I render vertical text?
• How do I render combined text?
• How do I automate quotation marks?
• How do I use the function format-number() in XSL?
• How do I represent a raw decimal number in XML?
• How do I use the <xsl:number/> element in XSL?
• How do I use the <xsl:sort/> element in XML?
• How do I separate rendering from tagging?
• Why should I use caution with <br/> and equivalent elements?
• Why should I use caution with text-transform in CSS and XSL?
• Why should I use caution with absolute positioning in CSS and XSL?

Localization:

• How do I translate XML documents?
• What are the guidelines to create XML document types that will be easier to localize?
• What are the guidelines to author XML documents that will be easier to localize?
• What are the features a translation tool for XML should have?
• How can I specify that elements with complex rules are translatable?
• How CDATA sections fare during translation?
• Is there any translatable text in a CSS style-sheet?
• Is there a standard set of localization directives? [changed]
• Can I see some examples of XML documents causing localization problems?

You can also find information related to XML internationalization and localization on the following online resources:

• The Internationalization Tag Set (ITS) Version 1.0 (W3C Recommendation)
• Extensible Markup Language (XML) 1.0 Second Edition (W3C Recommendation).
• Extensible Markup Language (XML) 1.1 (W3C Working Draft).
• Character Model for the World Wide Web 1.0 (W3C Working Draft).
• The W3C I18N GEO (Guidelines, Education and Outreach) Pages.
• The W3C Internationalization pages.
• XML Japanese Profile (W3C Recommendation).
• Unicode Normalization Forms (Unicode Standard Annex #15).
• Unicode in XML and other Markup Languages (Unicode Technical Report #20).
• Ruby Annotation (W3C Recommendation).
• Charlint, a Character Normalization Tool, by Martin Dürst.
• Localisation Considerations in DTD Design, by Richard Ishida.
• XML Technologies and the Localization Process, by Yves Savourel.
• Articles on Unicode and XML, by Robin Cover.
• The Unicode Web site.
• The XML links in i18ngurus.com.