Common Errors and What to Do About Them| Tag or Attribute | Not Supported By | Solution |
| ALINK | MSIE 2, MSIE 3. | Leave it. ALINK is nonessential. |
| DIV, SPAN, CLASS, STYLE, ID | Any pre-4.0 browser. |
Create a low-end page, or, depending on how the page looks
without the style, leave it alone. DIV contents are displayed
without style trappings by all browsers. |
| STYLE, CLASS | Any pre-4.0 browser. |
Create a low-end page, or, depending on how the page looks
without the style, leave it alone. |
| BLINK | Non-Netscape browsers. | Leave it alone. |
| EMBED, PARAM | MSIE 2. | Create low-end page or use alt image. For sound files, you may use the BGSOUND tag. (Note: EMBED always causes a warning telling you to double-check the parameters.) |
| BGSOUND | Non-MSIE browsers. | Use EMBED for Netscape browsers. |
| TABLE, TD, TR: BGCOLOR, Background image | Navigator 2.0. | Don't worry about it unless your text color won't show up on top of the page background color. |
| U | Navigator 2.0. |
Leave it alone, or use italics instead of underlining. |
| IMG ALIGN=absbottom, absmiddle | MSIE 2-4, Navigator 2.0. | View page in Explorer to evaluate impact and change attribute or create Explorer-centric version. |
| JavaScript | MSIE 2; some attributes not supported by other browsers. | Test in affected browser, if possible. Make non-JavaScript version or leave it alone if the code doesn't cause errors. (See Chapter 10.) |
| HR COLOR= | MSIE2; Navigator 2.0 and higher. | Ignore. |
| TABLE bordercolor | Navigator 2 and higher. | Use redundant bordercolorlight and bordercolordark attributes. |
| TABLE bordercolorlight, bordercolordark | MSIE 2-4. | Use redundant bordercolor attribute. |
| FRAME, FRAMESET, NOFRAMES | MSIE 2. | Create no-frames version of the page. Frames-incapable browsers will display the text enclosed in the NOFRAMES tag. |
| IFRAME | MSIE 2, Navigator 2.0 and higher. | Preview in Navigator; create Navigator version of page or ignore, depending on appearance. |
| FRAMEBORDER | MSIE 2-4. | Ignore. |
| BODY topmargin, leftmargin | Navigator 2.0 and higher. | Use frames or style sheets, or ignore. |
| APPLET | MSIE 2 | Offer non-Java version or use alt image. |
| OBJECT | MSIE 2-3, Navigator 2.0 and higher. | For Navigator, use EMBED tag. For older browsers, use alt images or a low-end page. |