In this section, you'll find an entry for every accepted element or "tag"(and entries for tags that are anticipated to be accepted) in the various HTML standards/extensions in use. Turn to Part I of this book to find out more about categories, compliance, and so on.
The HTML elements in this section are in alphanumeric sort, as you would expect to find in an encyclopedia. If a tag manipulates the visual presentation of a browser, a figure is provided to help illustrate the effect caused by the use of that tag.
Every effort has been made to build the most comprehensive and up-to-date reference of the HyperText Markup Language in encyclopedic format. Note that there are several related conventions that are not part of the HTML standard but that can be called up or manipulated from an HTML document. Many of the most advanced math elements and server-side includes, for example, are not part of the HTML standards now in development. The scope of this book is constrained to HTML standards observed by browsers offered by Netscape, Microsoft, and Mosaic and the HTML 2/HTML 3.2 standards.
New tags will be added to this book as they are recognized, adopted, and implemented in products such as Netscape Navigator, Internet Explorer, and Mosaic or as they're included in subsequent HTML standards.
Every effort has been made to document every HTML tag you may run across. While individual attributes may not be represented by specific entries (as do all tags), a few tag/attribute combinations merit a specific entry and have been granted one.
Most HTML tags fall into families or functional categories. Tag categories are being developed by standards and proposal groups in the hopes of organizing individual tag development and standard enhancement efforts into clearly defined areas for the focus of more specific groups of practitioners.
The categories defined in this section of the book coincide with the HTML 2 and HTML 3.2 specification categories with some minor modifications. The HTML 2 and HTML 3.2 specifications are thoroughly supported by Netscape and Microsoft. In addition, both companies have introduced their own enhancements in the form of tags called extensions.
As the HTML standards mature, individual categories are expected to proliferate and become areas of specialty for many HTML authors.
The following sections detail those categories and their descriptions.
This category includes the basic page formatting tags required in every HTML document.
Forms tags are specific to authoring works that accept or act on input from the person viewing a page.
Table support is new to HTML 2 and is not fully supported on earlier versions of HTML and older browser software.
Frames are an extension of Netscape's interpretation of the HTML 3.2 standard. Currently, proper authoring of frames requires the HTML author to write three sets of documents, each set readable by three classes of browsers: those that employ proprietary extensions, browsers that are HTML 3.2 compliant, and, of course, legacy browsers that do not render frames at all.
Structural definition takes advantage of the browser software's ability to format text without further input from the HTML document.
This category is host to tags that are not effectively included in other, more distinct categories.
Tags that are designed to work with characters that are not included in the lower ASCII character set are included in this category. The International Standards Organization (ISO) Latin characters are special characters.
This category includes the tags that manipulate background imagery and colors used in HTML documents.
Lists provide the HTML author with the ability to organize content in hierarchies within a document.
Dividers are objects that are employed by every browser to separate bodies of text or graphics in an HTML document.
This category includes all viewable images that must be rendered by a browser, not created by one. Links take that reader to another point in the same page or to another URL entirely.
The presentation formatting category includes all font handling tags that manipulate which font is used, which point size is used, which color is used, and so on.
Microsoft has presented another set of HTML tag categories that is closer to supporting Microsoft's goal for Internet Explorer's integration into every Microsoft application.
Many of the Netscape and Microsoft extensions are integrated into emerging HTML standards as they are revised. Correspondingly, some tags become obsolete because of disuse or poor performance.
At the time of this writing, Microsoft has done much to enhance the power of its HTML browser, Microsoft Internet Explorer. By introducing tags, such as <BGCOLOR>, which gives the Web author the ability to use shades of colors instead of just sixteen primary colors and <MARQUEE> that scrolls text across the browser's display, Web browsing has been made significantly more interesting.
The organization that actually sponsors HTML standards, W3C, did not include many tags that are proprietary extensions of HTML 2. If you want your Web pages to be rendered by the majority of browsers, consider avoiding the use of these extensions unless they are properly rendered by both of the latest versions of Netscape Navigator and Microsoft Internet Explorer.
Chapter 3, "HTML Reference," is the part of this book that describes HTML tags and attributes. Some tags include a graphic or a table. Other tags do not. Some tags occupy more than a single page so that they are documented properly.
The following sections describe the kind of information you can expect to find on each page in the HTML Reference Section.
This section displays the name of the HTML element described on that page or pages.
This section deals with compliance issues and the relevance to the content of the reference section. Icons are used to indicate whether readers can expect a given element to work properly if they are staying within the scope of these levels of compliance:
Netscape. This icon indicates that the latest versions of Netscape Navigator will render this element properly.
Internet Explorer. This icon indicates that the latest versions of Internet Explorer will render this element properly.
Mosaic/XMosaic. This icon indicates that the latest versions of Mosaic and XMosaic will render this element properly.
HTML 2. This icon indicates compliance with this set of standards.
HTML 3.2. This icon indicates compliance with this set of standards.
This section provides an example of how the covered element appears in an HTML document. Includes beginning and ending tags if both are used.
This section defines the use for the element as originally intended. Any general discussion of the element appears in this section.
This section provides an example of how the element is used in an actual line in an HTML document. Also, if a figure is displayed on the same page, every effort has been made to display the result of the example syntax in that Figure.
If a figure (screen shot and caption) imparts value in a visual way, it is included here. The "Example Syntax" section is used for this illustration.
If a figure is not useful, the "In Actual Use" section is not included.
If appropriate to the element being discussed, this section has a table that informs the reader of related HTML elements that can be used outside or inside the discussed element.
Some elements do not require a "Related Elements" section, in which case it will be omitted.