7. XHTML Structure Module

Contents

This section is normative.

The Structure Module defines the major structural elements for XHTML. These elements effectively act as the basis for the content model of many XHTML family document types. The elements and attributes included in this module are:

Elements Attributes Minimal Content Model
body Common (Heading | Block | List)*
head Common title
html I18N, profile (URI), xmlns (URI = "http://www.w3.org/2002/06/xhtml2") head, body
title I18N PCDATA

This module is the basic structural definition for XHTML content. The html element acts as the root element for all XHTML Family Document Types.

Note that the value of the xmlns attribute is defined to be "http://www.w3.org/2002/06/xhtml2". Also note that because the xmlns attribute is treated specially by XML namespace-aware parsers [XMLNAMES], it is legal to have it present as an attribute of each element. However, any time the xmlns attribute is used in the context of an XHTML module, whether with a prefix or not, the value of the attribute shall be the XHTML namespace defined here.

Implementation: DTD

7.1. The html element

After the document type declaration, the remainder of an XHTML document is contained by the html element.

Attributes

The I18N collection
A collection of attributes related to Internationalization, including the xml:lang.
profile = URI
This attribute specifies the location of one or more meta data profiles, separated by white space. For future extensions, user agents should consider the value to be a list even though this specification only considers the first URI to be significant. Profiles are discussed in the section on meta data.

7.2. The head element

The head element contains information about the current document, such as its title, keywords that may be useful to search engines, and other data that is not considered document content. User agents do not generally render elements that appear in the head as content. They may, however, make information in the head available to users through other mechanisms.

Attributes

The I18N collection
A collection of attributes related to Internationalization, including the xml:lang.

7.3. The title element

Every XHTML document must have a title element in the head section.

Attributes

The Common collection
A collection of other attribute collections, including: Core, Events, I18N, and Hypertext

Authors should use the title element to identify the contents of a document. Since users often consult documents out of context, authors should provide context-rich titles. Thus, instead of a title such as "Introduction", which doesn't provide much contextual background, authors should supply a title such as "Introduction to Medieval Bee-Keeping" instead.

For reasons of accessibility, user agents must always make the content of the title element available to users (including title elements that occur in frames). The mechanism for doing so depends on the user agent (e.g., as a caption, spoken).

Titles may contain entity references (for accented characters, special characters, etc.), but may not contain other markup (including comments). Here is a sample document title:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 2.0//EN"
   "http://www.w3.org/TR/xhtml2/DTD/xhtml2.dtd">
<html xmlns="http://www.w3.org/2002/06/xhtml2">
<head>
<title>A study of population dynamics</title>
... other head elements...
</head>
<body>
... document body...
</body>
</html>

7.4. The body element

The body of a document contains the document's content. The content may be presented by a user agent in a variety of ways. For example, for visual browsers, you can think of the body as a canvas where the content appears: text, images, colors, graphics, etc. For audio user agents, the same content may be spoken.

Attributes

The Common collection
A collection of other attribute collections, including: Core, Events, I18N, and Hypertext