Notice that when Dave Raggett discusses image backgrounds for tables at the end of section 10.11, he writes, "it is very possible that image backgrounds will also become standard features of HTML." He is talking about the future. For now, when you submit a page with table background to a validation program, it will not pass the test as standard html. For example, the page in unit 6 describing alt tags used a nested one-cell table with a "stone" background. Because of the table background, that is one of the pages in this class series that does not display the icon at the bottom indicating that it has validated html 4.0.
Here is why table backgrounds are not yet part of standard html. It is because of the dueling browsers, of course. Consider how the following code might display:
<table width="50%" border="1"
background="flower.gif" align="center" >
To see a full-screen version of how this displays, click on this link to the Table with Background Display. Be sure to look at it with both a Netscape and Explorer browser. What you see will depend on what version of the browsers you look at. The main point to note is that you cannot necessarily predict what your viewer will see.
Copyright by dwang, 1999, 2000. All rights reserved.