Web style sheets were made available several years ago, but eager Web authors opted for Netscape's proprietary extensions rather than the more powerful, more standard style sheets. The tide is turning, however. The number of Web browsers that support style sheets is on the rise, and, therefore, more Web authors are understanding the power of style sheets, allowing the authors to influence document presentation while preserving platform independence. Because of the more widespread use of style sheets, the following standardization issues have surfaced:

PRESENTATION ISSUES:

Style sheets were never intended to allow the author to completely control the presentation of a document; their purpose is only to influence the presentation of the document. Some authors use a technique referred to as "drop shadow", which uses negative margins and relies heavily upon the style sheet. If the user's browser does not support style sheets or the user has turned style sheets off, pages using drop shadow or other style sheet-related techniques are often rendered unreadable. Due to the unpredictable nature of the Web, authors must be careful to not have their documents be so dependent on style sheets that they are not even readable when the style sheet is unavailable (http://www.htmlhelp.com/reference/css/dependence.html.)

STANDARDIZING WARNING AND NOTIFICATION PROCEDURES:

When a given Web browser is unable to properly render a certain document created with a style sheet, it is possible that the browser can warn the reader that the style sheet was not able to be completely followed. Depending on the situation, it is possible that the user will receive so many warnings that the user will become too frustrated to even continue reading the document. There are times, however, when the warnings are necessary, such as when the content unable to be displayed is of a legal or otherwise important nature.

It is also possible for the user to turn off style sheet downloading, in which case it is possible that some content that is of a legal or otherwise important nature will not be downloaded due to the absence of the style sheet. This, too, is something that the user must be made aware of when viewing documents created with style sheets when the user instructs the browser to not download style sheets.

If the browser cannot render certain colors specified in the style sheet, the browser must provide some kind of contrast so all text is legible, but warning the user of this situation is unnecessary.

Suffice it to say that much consideration must be given to when and how often the user is warned that a style sheet is unable to be completely rendered by the user's browser of choice or if the user disables the browser so it does not download style sheets.

STANDARDIZING TABLE HANDLING:

If conflicts occur when a user's browser is displaying a table, the most important factor to consider is displaying the table information in as clear a manner as possible. When certain constructs do not display properly, the browser must err on the side of clarity, rather than trying to show different types of separation lines, grid lines, etc. to approximate the display method specified in the style sheet.

STANDARDIZING THE HANDLING OF CACHING STYLE SHEETS:

Because a style sheet can potentially apply to numerous documents, possibly more than can be contained in the user's browser's disk cache, it is possible that during the course of downloading, the style sheet, which is downloaded prior to any of the documents, will expire from the disk cache. A separate cache area for style sheets only is one method that can be used to help resolve this problem. The "black and white" nature of style sheet usage in browsers (they're either used or not used) also needs some work. One suggestion is to use a three-tiered approach, where the user can specify that the browser use all style sheets, use only those in cache, or use no style sheets at all.

STANDARDIZING READER-AUTHOR CONFLICT RESOLUTION:

The user must always have the ability to modify any style sheet at any time to customize the appearance of any style-enabled document. When a conflict exists between what the author specifies in one part of the style sheet and what the user specifies in another part, however, the author specification must take precedence. If the user is unhappy with this precedence, the style sheet may still be further modified to accommodate the user's preferences.

http://www.eit.com/www.lists/www-style.1995/0235.html

GOALS FOR A STYLE SHEET FORMAT:

In summary, regardless of which style sheet standard is adopted, the following list of goals suggested by James Clark, creator of Jade, a DSSSL implementation, are good to refer to while said standard is being developed:

• It should be rich enough to be able to get reasonable presentation of SGML documents using a wide range of real DTDs.
• It would not be a goal to support every presentation style that anybody can dream up.
• It should be simple to be attractive to the Web community.
• It should be simple enough that it can be quickly implemented in a wide variety of products.
• There should be a smooth path to style sheets with much greater functionality.
• An entirely graphical style sheet editor should be possible. It should be possible to make the
• actual syntax of the style sheet completely invisible to users. However, it should also be
• possible for technical users to edit the style sheets directly.
• The emphasis should be on online delivery, but very simple hardcopy should also be possible.

(http://www.falch.no:80/people/pepper/DSSSL-Lite/dl-goals.html.)

BEYOND CSS1

Future extensions to CSS1 (and, most likely, other style sheet formats) are aimed at bringing better support for printing Web pages, styles for speech and Braille output, layout, fonts, and device-independent colors. CSS1 in its present form has generated some concern among Web authors; imagine the concern in the future when CSS1 begins to affect how the handicapped view Web pages! (http://htmlhelp.com/reference/css/stylesheets-now.html.)

CONCLUSION

In this age of growing pains for the World Wide Web, style sheets may very well prove to be one of the key items used to help resolve said pains. As discussed above, there is also the potential for style sheets to cause some pain of their own. Since style sheets are still in their infancy, now is the time to revisit the underpinnings of style sheet standards and ensure that they adequately meet the needs of the World Wide Web community at large and truly solve problems rather than causing more of their own.

Introduction

Explanation of Style Sheets

IT Standards Home
February 27, 1997
Final Version
thomsone@timken.com