HTML4.01规范中英文对照-HTML4简介(2)

2.3 HTML 4

HTML 4 extends HTML with mechanisms for style sheets, scripting, frames, embedding objects, improved support for right to left and mixed direction text, richer tables, and enhancements to forms, offering improved accessibility for people with disabilities.

HTML 4 在样式表机制，脚本，框架，嵌入式对象，从右向左以及混合文本方向的更好支持，更丰富灵活的表格以及表单增强，为生理缺陷人士提供给更好的访问能力等方面都对HTML进行了扩展。

HTML 4.01 is a revision of HTML 4.0 that corrects errors and makes some changes since the previous revision.

HTML4.01是HTML4.0的修订版本，它修正了一些错误以及自从上次修订的一些变更。

2.3.1 Internationalization

This version of HTML has been designed with the help of experts in the field of internationalization, so that documents may be written in every language and be transported easily around the world. This has been accomplished by incorporating [RFC2070], which deals with the internationalization of HTML.

该版本的HTML在设计时得到了国际化领域专家的帮助，所以HTML文档可以用任何的语言来撰写并且这些文档可以很容易的在世界范围内传播。在处理HTML国际化问题时，我们引入了[RFC2070],所以该版本的HTML获得了上述能力。

One important step has been the adoption of the ISO/IEC:10646 standard (see [ISO10646]) as the document character set for HTML. This is the world's most inclusive standard dealing with issues of the representation of international characters, text direction, punctuation, and other world language issues.

一个很重要的步骤是将ISO/IEC：10646(参见[ISO10640])标准作为HTML的文档字符集。该标准用于处理国际化字符、文本方向，标点以及其他世界性语言问题。该标准在世界范围内已经被广泛接受。

HTML now offers greater support for diverse human languages within a document. This allows for more effective indexing of documents for search engines, higher-quality typography, better text-to-speech conversion, better hyphenation, etc.

当今的HTM对在一个文档内采用多种人类语言提供了更强大的支持。这种支持使得搜索引擎对文档的索引更加有效，排版更加高质量，文本语音转换更加先进，更好的断字等等。

2.3.2 Accessibility

As the Web community grows and its members diversify in their abilities and skills, it is crucial that the underlying technologies be appropriate to their specific needs. HTML has been designed to make Web pages more accessible to those with physical limitations. HTML 4 developments inspired by concerns for accessibility include:

随着Web世界的增长，它的成员在他们个人能力以及技能上千差万别，所以底层的技术应该可以满足他们的特殊需要是非常关键的。HTML已经被设计成对于那些有生理缺陷的人们访问网页变得容易。HTML4在访问性方面的关注点主要集中在如下几个方面：

• Better distinction between document structure and presentation, thus encouraging the use of style sheets instead of HTML presentation elements and attributes.
• 更好的文档结构与文档展现隔离，这促使应用样式表(Style sheets)而不是采用HTML的展现元素和属性来解决文档的展现问题。
• Better forms, including the addition of access keys, the ability to group form controls semantically, the ability to group SELECT options semantically, and active labels.
• 更好的表单，这些特性包括增加了访问快捷键，根据语义来对表单控件进行分组的能力，根据语义来对SELECT选项进行分组的能力以及活动标签（acitve labels）
• The ability to markup a text description of an included object (with the OBJECT element).
• 对于通过OBJECT元素包含的对象提供文本描述的能力
• A new client-side image map mechanism (the MAP element) that allows authors to integrate image and text links.
• 全新的客户端图像地图机制(MAP元素），该机制允许作者将图像与文本链接整合起来。
• The requirement that alternate text accompany images included with the IMG element and image maps included with the AREA element.
• 在IMG元以及在AREA元素内的图像可以与一个替代的文本想链接。
• Support for the title and lang attributes on all elements.
• 对于所有元素都提供title和lang属性支持
• Support for the ABBR and ACRONYM elements.
• 支持ABBR（缩略语）和ACRONYM（首字母缩略）元素
• A wider range of target media (tty, braille, etc.) for use with style sheets.
• 在样式表中提供了更广泛的目标介质（如：字符介质，盲文机子等）
• Better tables, including captions, column groups, and mechanisms to facilitate non-visual rendering.
• 更好的表格，这些特性包括标题，列分组以及简化非可视化输出的机制等。
• Long descriptions of tables, images, frames, etc.
• 为表格，图片，框架等提供长文本描述。

Authors who design pages with accessibility issues in mind will not only receive the blessings of the accessibility community, but will benefit in other ways as well: well-designed HTML documents that distinguish structure and presentation will adapt more easily to new technologies.

那些在脑海里一直想着页面访问性的HTML文档作者不但可以收到访问社会的祝福，另外还可以获得如下几方面的收获：一个设计优秀的区分结构与展现的文档将会更加容易的引入新的技术。

Note. For more information about designing accessible HTML documents, please consult [WAI].

注释。有关设计易于访问的HTML文档的信息，请咨询[WAI].

2.3.3 Tables

The new table model in HTML is based on [RFC1942]. Authors now have greater control over structure and layout (e.g., column groups). The ability of designers to recommend column widths allows user agents to display table data incrementally (as it arrives) rather than waiting for the entire table before rendering.

而今的HTML提供了一个基于[RFC1942]的表格模型。文档的作者拥有针对于表格结构与布局的更加强大的控制能力（比如：列分组）。通过表格的设计者给出建议的列宽，用户代理（浏览器）可以增量地显示表格数据，而不是等到正个表格数据全部接受到才显示。

Note. At the time of writing, some HTML authoring tools rely extensively on tables for formatting, which may easily cause accessibility problems.

注释。在写这篇文档时，一些HTML撰写工具相当依赖于表格来进行文档格式化，这会非常容易导致可访问性问题。

2.3.4 Compound documents

HTML now offers a standard mechanism for embedding generic media objects and applications in HTML documents. The OBJECT element (together with its more specific ancestor elements IMG and APPLET) provides a mechanism for including images, video, sound, mathematics, specialized applications, and other objects in a document. It also allows authors to specify a hierarchy of alternate renderings for user agents that don't support a specific rendering.

HTML现在提供了标准的机制用于将常见的媒体对象以及应用程序嵌入见HTML文档。OBJECT元素（以及它的更加专用的前辈元素IMG和 APPLET）提供了在文档内包含图片，视频，语音，数学公式，专用应用程序以及其他各种类型对象的机制。HTML还允许文档撰写者提供一个备选的展现层 级，当用户代理（浏览器）不支持摸个对象展现的时候可以在这个层级上逐级识别进行展现。

2.3.5 Style sheets

Style sheets simplify HTML markup and largely relieve HTML of the responsibilities of presentation. They give both authors and users control over the presentation of documents -- font information, alignment, colors, etc.

样式表简化了HTML的标签同时也极大地减轻了HTML在展现方面的职责。他们把文档展现的控制交给了作者和用户——比如字体信息，对齐方式，颜色等等。

Style information can be specified for individual elements or groups of elements. Style information may be specified in an HTML document or in external style sheets.

样式信息既可以针对某个特定的单个元素也可以针对一组元素。样式信息既可以在HTML文档内声明也可以在一个外部的样式表内声明。

The mechanisms for associating a style sheet with a document is independent of the style sheet language.

将样式表和文档关联的机制是独立于样式表语言的。

Before the advent of style sheets, authors had limited control over rendering. HTML 3.2 included a number of attributes and elements offering control over alignment, font size, and text color. Authors also exploited tables and images as a means for laying out pages. The relatively long time it takes for users to upgrade their browsers means that these features will continue to be used for some time. However, since style sheets offer more powerful presentation mechanisms, the World Wide Web Consortium will eventually phase out many of HTML's presentation elements and attributes. Throughout the specification elements and attributes at risk are marked as "deprecated". They are accompanied by examples of how to achieve the same effects with other elements or style sheets.

在样式表发明以前，HTML文档的作者在展现方面只有很弱的控制能力。HTML3.2包含了一些用于控制对齐方式，字体大小和文本颜色的一些属性和元素。 同时HTML文档的作者还是需要用表格和图片的作为网页布局的方法。如果用户在一段较长的时间内部升级他们的浏览器，就意味着这些特性还要被使用很长时 间。然而，既然样式表已经提供了更加强大的展现机制，万维网联盟将会清除掉众多有关HTML展现的元素和属性。在本文档内所有这方面的元素和属性将被标记 为"不推荐使用"。并给出实现同样效果的替代方案，这些方案是用其他的元素或样式表实现的。

2.3.6 Scripting

Through scripts, authors may create dynamic Web pages (e.g., "smart forms" that react as users fill them out) and use HTML as a means to build networked applications.

通过script脚本，HTML作者可以创建动态的网页（比如：用于相应用户填报的"智能表单"）以及用HTML作为构建网络应用的工具。

The mechanisms provided to include scripts in an HTML document are independent of the scripting language.

在HTML文档内包含script脚本的机制与脚本语言本身无关。

2.3.7 Printing

Sometimes, authors will want to make it easy for users to print more than just the current document. When documents form part of a larger work, the relationships between them can be described using the HTML LINK element or using W3C's Resource Description Framework (RDF) (see [RDF10]).

有些时候，HTML作者非常希望除了打印当前文档外还可以打印其他相关的文档。并希望这样的操作可以非常容易。当很多文档构建一个大的网络时，他们之间的关系可以通过HTML的LINK元素或者W3C的资源描述框架(RDF）来表述（参见[RDF10]）。

2.4 Authoring documents with HTML 4

We recommend that authors and implementors observe the following general principles when working with HTML 4.

我们建议所有的HTML作者和实现者在用HTML4工作时能够检视本节的如下通用准则。

2.4.1 Separate structure and presentation

HTML has its roots in SGML which has always been a language for the specification of structural markup. As HTML matures, more and more of its presentational elements and attributes are being replaced by other mechanisms, in particular style sheets. Experience has shown that separating the structure of a document from its presentational aspects reduces the cost of serving a wide range of platforms, media, etc., and facilitates document revisions.

HTML的根是SGML。SGML从一开始就是一种用户表述结构的标记语言。随着HTML的成熟，越来越多的有关展现的元素和属性已经被诸如样式表等其他 机制所取代。经验已经表明将文档的结构与其展现方面分离将在降低在多个平台、介质等方面传播的成本，以及简化文档的修订。

2.4.2 Consider universal accessibility to the Web

To make the Web more accessible to everyone, notably those with disabilities, authors should consider how their documents may be rendered on a variety of platforms: speech-based browsers, braille-readers, etc. We do not recommend that authors limit their creativity, only that they consider alternate renderings in their design. HTML offers a number of mechanisms to this end (e.g., the alt attribute, the accesskey attribute, etc.)

为了每个人都可以而更加容易访问Web，特别是那些有生理缺陷的人们，HTML的作者需要关注他们的文档在不同的平台上如何被展现，这些平台包括：基于语 音的浏览器，盲文阅读器等等。我们不建议作者限制他们的创造力，HTML为了满足这些需求提供了多种可供选择的机制（比如：alt属 性，accesskey属性等等）以保证他们不仅仅是只涉及一种替代方式。

Furthermore, authors should keep in mind that their documents may be reaching a far-off audience with different computer configurations. In order for documents to be interpreted correctly, authors should include in their documents information about the natural language and direction of the text, how the document is encoded, and other issues related to internationalization.

更进一步，作者应该一直想着他们的文档可能正在到达一个遥远的拥有完全不同电脑配置的受众。为了使文档可以被正确的解释，作者应该在他们的文档中包含自然语言以及文本方向，文档如何被编码以及其他有关国际化的信息。

2.4.3 Help user agents with incremental rendering

By carefully designing their tables and making use of new table features in HTML 4, authors can help user agents render documents more quickly. Authors can learn how to design tables for incremental rendering (see the TABLE element). Implementors should consult the notes on tables in the appendix for information on incremental algorithms.

通过仔细地设计他们的表格以及使用HTML4提供的有关表格的新的特性，作者可以帮助用户代理（浏览器）更快的展现表格。作者可以学习一下如何设计一个增量展现的表格（参见TABLE元素）。HTML实现者应该参考在本文档附录里寡欲表格增量展现机制的相关注释信息。