Authoring Techniques for XHTML & HTML Internationalization 1.0
Checklist format

Use the meta element in HTML documents to explicity declare the document's character encoding.

The meta declaration must only be used when the character encoding is organized such that ASCII-valued bytes stand for ASCII characters (at least until the meta element is parsed).

meta declarations should appear as early as possible in the head element.

Use the lang and xml:lang attributes in the html tag.

A document encoding SHOULD be chosen which maximizes the opportunity to directly represent characters and minimizes the need to represent characters by markup means such as character escapes.

Encode web pages in UTF-8 unless there is a good reason not to.

Use IANA's preferred names for charset declarations.

Use character sets and encodings that will be accessible and common to your users.

Use the meta element in HTML documents to explicity declare the document's character encoding.

The meta declaration must only be used when the character encoding is organized such that ASCII-valued bytes stand for ASCII characters (at least until the meta element is parsed).

meta declarations should appear as early as possible in the head element.

Escapes SHOULD be avoided when the characters to be expressed are representable in the character encoding of the document.

Content SHOULD use the hexadecimal form of character escapes when there is one.

If, for a specific application, it becomes necessary to refer to characters outside [ISO10646], characters should be assigned to a private zone to avoid conflicts with present or future versions of the standard. This is highly discouraged, however, for reasons of portability.

Don't use entities in XHTML?

Something about the use of inline images to represent characters

Some guidelines for content authors who know that users won't have all the necessary fonts.

Use the lang and xml:lang attributes in the html tag.

Use the lang and xml:lang attributes around the text.

Use the hreflang attribute on the a element.

Follow the guidelines in RFC3066.

Use the two letter ISO 639 codes for the language code and the two letter ISO 3166 codes for the country code wherever possible.

Add dir="rtl" to the html tag.

Enter all text in a single logical order, and leave it to the Unicode bidirectional algorithm to order the text as appropriate

If using an ISO encoding, choose iso-8859-8-i. (Alternatively use utf-8 or utf-16.)

Add the dir attribute to an element that encompasses all the text.

Use markup to achieve bidirectional effects rather than CSS styling or the Unicode control characters for bidi embedding.

Use the bdo element to force the directionality of a sequence of inline characters.

Use the special entities, ‎ and ‏ to force directionality of directionally neutral characters.

• Always use a four-digit number for the year.

• Always use words (abbreviated if necessary) for the month.

For forms, use structured fields or popup menus for time and date input.