When validating XHTML markup with the W3C Validator, there are a few easy ways to quickly reduce the number of errors it finds:
- Specify a DOCTYPE
- Specify the Character Encoding
- Write all HTML tags and Attribute Names in lower case eg: use table not TABLE and use height=”1″ not HEIGHT=”1″
- Encode HTML character entities like the ampersand character & properly, always use & in place of &
- Quote all attribute values even those that are numeric eg: use <td rowspan=”3″> not <td rowspan=3>
- Empty tags like <hr> and <br> must be replaced with <hr /> and <br />. Note: older versions of Netscape cant interprete the <br/>
tags. Typing a space before the / in <br /> fixes this problem.

{ 2 comments… read them below or add one }
Nice getting started tip, w3c own refrence isnt to sharp all the time.
validating a xhtml script can sometime becomes tiresome. I have found that most people simply code first and never care for validation.