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Authoring Techniques for XHTML & HTML Internationalization: Outline View

This document provides techniques, in outline form, for content authors working with XHTML, HTML and CSS. Click on the text of a technique to link to a detailed explanation. See the notes on document use for additional information.

Language

Declaring the text processing language

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	Always declare the default text processing language of the page, using the html tag, unless there are more than one primary languages.
•	Use the lang and/or xml:lang attributes around text to indicate any changes in language.
•	Do not use Content-Language to declare the default text processing language, ~~and do not~~ use language attributes ~~to declare the primary language metadata~~.
•	Do not declare the language of a document in the body tag.
•	For HTML use the lang attribute only, for XHTML 1.0 served as text/html use the lang and xml:lang attributes, and for XHTML served as XML use the xml:lang attribute only.
•	If the text in attribute values and element content is in different languages, consider using a russian doll approach.
•	For documents with multiple primary languages, decide whether you want to declare a single text processing language in the html tag, or leave it undefined.

Specifying primary language metadata

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	Consider using a Content-Language declaration in the HTTP header or a meta tag to declare metadata about the primary language of a document.

Documents with multiple primary languages

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	~~If you are~~For documents with multiple primary languages, consider using Content-Language to indicate the primary language metadata ~~when there are multiple primary languages, provide~~ with a comma-separated list of all primary language tags.
•	For documents with multiple primary languages, try to divide the document at the highest possible level, and declare the appropriate text processing language in those blocks.

Choosing language values

		Sa
•	Follow the guidelines in RFC3066 or its successors for language attribute values.
•	Use the two-letter ISO 639 codes for the language code where there are both 2- and 3-letter codes.
•	Consider using the codes zh-Hans and zh-Hant to refer to Simplified and Traditional Chinese, respectively.	?

Identifying in-document language changes

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	Use the lang and/or xml:lang attributes around text to indicate any changes in language.
•	For HTML use the lang attribute only, for XHTML 1.0 served as text/html use the lang and xml:lang attributes, and for XHTML served as XML use the xml:lang attribute only.

Indicating the language of a link destination

		Sa
•	When pointing to a resource in another language, consider the pros and cons of indicating the language of the target document.	?
•	If you want to indicate that the target document of an a element is in another language, consider using hreflang with CSS.~~When pointing to a resource in another language, consider the pros and cons of using CSS to indicate the language, based on the value of the hreflang attribute of the a element.~~	?
•	~~If using CSS to generate a language marker from the hreflang attribute, d~~Do not use flag icons to indicate languages.

Character sets, character encodings and entities

Choosing a page encoding

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	Choose UTF-8 or another Unicode encoding for all content.
•	If you don't use a Unicode encoding, select an encoding that best supports the languages / characters to be included in the page text. What does this mean? Does it mean, which maximizes the opportunity to directly represent characters and minimizes the need to represent characters by markup means such as character escapes? Does it include the idea that you should choose the most commonly used encoding for a region?
•	Check that user agents (all agents that must render the page) adequately support the page encoding that you have selected. If not, you might need to use a more widely supported encoding to achieve an adequate degree of user agent support. Couldn't this be rolled into the previous technique?
•	Use character sets and encodings that will be accessible and common to your users.

Specifying a page encoding

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	Always declare the encoding of your documents.

Using the HTTP header

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	Where appropriate, declare the page's character encoding by setting the charset parameter in the HTTP Content-Type header.
•	If declaring the character encoding in the HTTP header, ensure that the server-side settings will be maintained, especially if the file is moved or the server technology is changed.
•	If declaring the character encoding in the HTTP header, always declare the encoding inside the document too.

Declaring the encoding in-document

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	For HTML documents and XHTML documents served as text/html, always use a meta element to explicitly declare the document's character encoding.
•	Use meta charset declarations as early as possible in the head element.
•	For XHTML served as application/xhtml+xml, always use an XML declaration with an encoding attribute.
•	For XHTML served as text/html, where practical use an XML declaration with an encoding attribute.
•	If you serve an XHTML file without an encoding declaration in the HTTP header or the XML declaration, you must use either UTF-8 or UTF-16 as the document encoding.

Other

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	If you declare the document's character encoding in more than one place, take steps to ensure that it is always correct.
•	Use the preferred names from IANA's charset registry.
•	Do not invent your own encoding names using the x- syntax.

Representing characters using escapes

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	Only use escapes for characters in exceptional circumstances. Create pages using an encoding that supports all the characters you need.
•	Ensure that numbers in numeric character references always reference a Unicode codepoint.
•	When using escapes, use the hexadecimal form.
•	Use numeric character references rather than entities if your document is to be processed by unknown XML tools or converted to XML.
•	If you use escapes, to represent characters in a style attribute consider using CSS escapes, rather than NCRs or entities.

Bidirectional text

Enabling easy localization for RTL scripts

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	Whenever possible, avoid HTML attributes with values of right and left. Use CSS in a linked stylesheet instead.

General use of bidi markup

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	Do not use CSS styling to control directionality in XHTML/HTML. Use markup.
•	Only use bidi markup where it is needed.

Basic setup for pages in RTL scripts

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	Add `dir="rtl"` to the html tag any time the overall document direction is right-to-left.
•	Do not add `dir="rtl"` to the body tag.
•	Use logical order, not visual ordering for Hebrew.
•	If using an ISO character encoding for Hebrew, choose iso-8859-8-i and use logical ordering.

Changing the directionality of a block element

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	Add the dir attribute to a block level element (only) to change its directionality.

Mixing text direction inline

		IEw	FFox	Moz	Op	NN	Sa	IEm
•	Use a Unicode right-to-left mark (RLM) or left-to-right mark (LRM) to make neutral characters such as punctuation and spaces appear in the right place when they fall between different directional runs.
•	Use a Unicode right-to-left mark (RLM) or left-to-right mark (LRM) to correctly order separate runs of same direction text separated by neutral characters such as punctuation and spaces.
•	Use the dir attribute on an inline element to resolve problems with nested directional runs.
•	For attribute text or element text that allows no internal markup, use Unicode control characters for bidirectional control.
•	Do not use Unicode control characters for bidirectional control if markup is available.
•	Do not leave white space at the end of inline elements that mark a directional boundary.

Notes on document use

This document is in early draft form. It is undergoing constant and frequent modification and does not yet contain accurate content.

Use the icons to the right of each section header to view the full text or view resources for a given section.

The yellow cells to the right indicate whether a technique is supported by a given user agent. The possible alternatives are:

Y : the earliest version of the user agent considered for this document supports the technique. Earliest versions are: Internet Explorer 6, Netscape Navigator 7, Opera 7
- : not supported
(digit): supported in version X and above
(blank space): needs further investigation.

Editor: Richard Ishida.

Content created 15 March, 2004. Last update 2005-02-07 17:35

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