XHTML stands for EXtensible HyperText Markup Language, and basically, is a combination of elements from HTML 4.01 with the syntax of XML. XML is a stricter and more rigourous markup language than HTML, requiring everything to be marked up correctly, for example, there must always be a beginning and end tags. As a result, XHTML written documents are “well-formed” making it easier to maintain and support.
Some of the rules of XHTML 1.0 include:
- Elements and attributes must appear in lower case
- Attribute values must be quoted
- Non-Empty elements require a closing tag
- Empty elements are terminated using a space and a trailing slash
- No attribute minimization is allowed
- In strict XHTML, all inline elements must be contained in a block element
Resource
1. http://www.webstandards.org/learn/articles/askw3c/oct2003/
2. http://w3schools.com/xhtml/xhtml_intro.asp
3. http://www22.brinkster.com/beeandnee/techzone/articles/htmltoxhtml.asp
4. http://www.sitepoint.com/article/future-html-xhtml
