Joomla! Documentation™

The definitive source for web standards is no doubt the World Wide Web Consortium; their web site is http://www.w3.org .In that site you can find many documents defining existing and proposed standards; however, you need to be aware that these documents are very technical in nature and you are likely to get confused if you are not used to reading technical documents. Other sites that may be of interest are http://www.webstandards.org and http://webstandardsgroup.org