Level 3 HTML Summary

The specification of Level 3 HTML is still largely in development, so this document should be considered a brief glance at what may come for HTML Level 3. Only a selection of the current proposed elements are shown here; and not all attributes of each are shown.

When completely defined, the Level 3 specifications will be additions over Level 0, Level 1, and Level 2 elements. In this document, the Level 3 elements listed are in all capital letters; the attributes are indicated by initial capital letters. In order to benefit from the information in this file, view both its HTML source as well as its rendered form in a Web browser. The tags are explained in the list below as well as demonstrated in this file.

HTML structure and comment elements

Level 3 specifies no additions over Level 0, 1, or 2.

The HEAD and Related Elements

• LINK:
  Extensions to the Rel attribute; Rel can be used to define a series of values for browser toolbar or other buttons:
  • Rel = Home; defines the home page link relative to this document
  • Rel = ToC; table of contents link
  • Rel = Index; an index
  • Rel = Glossary; the glossary of terms
  • Rel = Copyright; the copyright statement
  • Rel = Up; the parent document
  • Rel = Next; the next document to visit in a "tour"
  • Rel = Previous; the previous document in a "tour"
  • Rel = Help; a link to a help document or service
  • Rel = Bookmark; a link to a list of key links for the document
  • Rel = StyleSheet; a stylesheet (also available directly from http://www.w3.org/pub/WWW/Style/)
    to control the rendering of the current document
• STYLE: This element provides a way for the author of a document to define rendering information which will override client defaults and LINKed style sheets. Its one attribute, Notation, specifies an entity identifying an SGML description of the style.

The BODY and Related Elements

• Most BODY elements can use these attributes:
  • Id: an SGML identifier used for naming parts of the document in style sheets; also can be used as the target for a hypertext link; Id values must be unique within a document.
  • Lang: An ISO (International Organization for Standardization) abbreviation for the human language used in the text (e.g., "en.uk" for English as spoken in the United Kingdom). The first part of the code is the language as defined in ISO 639. The second part of the code is the two-letter country code from ISO 3166. This can be used by browsers to select from among a variety of choices for the document.
  • Class: This attribute defines an element as a particular kind of text sequence that can be then used in style sheets. The class designation can also be used in searching.
  • Background: This attribute can specify the image tile to appear in the document background.
• BODY elements:
  • DIV: used with the Class attribute to represent containers, or sections, of a document. For example, the Banner should be rendered in a browser so that it is always "on screen":
    <DIV CLASS=Banner>Company Confidential--do not disseminate</DIV>
  • TAB: used to control horizontal positioning. Attribute "Id" to define a tabstop; attribute "To" to move to a tabstop:

    This is the stop <TAB Id=T1> where the tab <BR>
    <TAB To=T1>will move the text.
    	

    rendered in a Level 3 browser as:
    

    This is the stop where the tab 
    		 will move the text.
    	

    Your browser renders this as:
    This is the stop where the tab
    will move the text.

  • A: anchors: more attributes:
    • Md: specifies a message digest (cryptographic checksum) for document defined by Href.
    • Shape: used within figures to define regions corresponding to a link to the document defined by Href.
  • information typing elements
    • DFN: the defining instance of a term
    • Q: a short quotation
    • LANG: the (human) language currently defined
    • AU: the name of an author
    • PERSON: names of people
    • ACRONYM: acronyms in the document
    • INS: inserted text (e.g., when documents are amended)
    • DEL: deleted text (e.g., when documents are amended)
  • font style elements
    • BIG: big print relative to current font
    • SMALL: smaller print relative to current font
    • SUB: a subscript
    • SUP: a superscript
  • FIG: used to define figures with captions; example:

    <FIG Src="../images/stats.gif">
       <P><CAPTION>Example Figure</CAPTION>
       <P><CREDIT>J. December</CREDIT>
    </FIG>
    	

    Your browser renders this as:
    

    Example Figure

    J. December

  • TABLE: used to define tables; example:

    <TABLE Border>
       <CAPTION>August Standings</CAPTION>
       <TR><TH Rowspan="2"><TH Colspan="2">Totals</TR>
       <TR><TH>Wins<TH>Losses</TR>
       <TR><TH Align="left">White Sox<TD>22<TD>55</TR>
       <TR><TH Align="left">Tigers<TD>84</TD><TD>8</TD></TR>
    </TABLE>
    	

    Is rendered in your current browser as:
    

    August Standings

    	Totals
    	Wins	Losses
    White Sox	22	55
    Tigers	84	8

    This would be rendered, in a Level 3 browser something like this:

    	August Standings
    +-------------------------------+
    |           |      Totals       |
    |           |-------------------|
    |           |  Wins   |  Losses |
    |-----------+---------+---------|
    | White Sox |   22    |    55   |
    |-----------+---------+---------|
    | Tigers    |   84    |     8   | 
    +-------------------------------+
    

    
    TABLE Attributes:
    • Align: the horizontal alignment of the table on the screen (not the contents of the table). Possible values are:
      • bleedleft: aligned at the left window border
      • left: at the left text margin
      • center: centered between text margins
      • right: at the right text margin
      • bleedright: aligned at the right window border
      • justify: table should fill space between text margins
    • Border: causes browser to render a border around the table; if missing, the table has no grid around it or its data.
    • Width: specifies how wide the table will be; if given as "NN%", the width is NN% of the width of the display.
    • Colspec: specifies the alignment of items in the columns; for example, Colspec="Lnn Rnn Cnn" specifies that column contents of column 1 are to be aligned left, column 2 right, and column 3 centered. The "nn" specifies the column width in Units.
    • Units: identifies the units to be used in measurements; default is "en," (a typographical unit approximately 1/2 of a point); other values are "relative" for setting the relative width of columns
  • CAPTION: used to label a figure or table
    Attributes:
    • Align: position of the caption relative to figure or table; values include "top," "bottom," "left," or "right."
  • TH: identifies a table header cell; and TD: identifies a table data cell;
    Both have Attributes:
    • Align: horizontal alignment of the paragraphs in a table row; values include "left," "center," "right," "justify," and "decimal" (text aligned on decimal points).
    • Valign: vertical alignment of material in a cell. Values include "top," "middle," "bottom," "baseline."
    • Colspan: the number of columns the cell spans.
    • Rowspan: the number of rows the cell spans.
    • No wrap: prevents the browser from wrapping the contents of the cell.
  • TR: identifies a container for a row of table cells;
    Attributes: same as for TH and TD.
  • TABLE Tips:
    • Table data can be lists, images, Forms, and other elements.
    • TH element is typically rendered as bold text.
    • TD element is typically rendered as regular weight text.
    • Always use TR's as "holders" for TH's and TD's.
    • The browser sets the number of columns in a table to be the greatest number of columns in all the row. Blank cells are used to fill any extra columns in the rows.
    • Netscape introduces table extensions.
  • MATH: to represent mathematical expressions. For example, the integral from a to b of f(x):

    <MATH>∫a_^b^{f(x)} dx</MATH>
    	

    Your browser renders this as:
    $dx$

References

• HyperText Markup Language Specification Version 3.0
  at http://www.hpl.hp.co.uk/people/dsr/html/CoverPage.html.
• The HTML 3.0 Hypertext Document Format -- a presentation slideshow
  at http://www.w3.org/pub/WWW/Arena/tour/start.html.
• Level 3 DTD
  at http://www.halsoft.com/sgml/html-3.0/DTD-HOME.html.

Copyright © 1995 by John December. All rights reserved.

Hyperlinks: Table of Contents