HTML and CSS Reference
Figure 1-5 Your web page passed validation as HTML5.
Does Your Code Always Have to Validate?
Validation is a great tool for web developers, but it is just that, a tool. There will be times when it is not realistic to
produce pages that pass validation. Sometimes there are small little hacks that you will have to write in order to get
some browsers (read: IE) to play ball, and these will show up as errors when you come to validate your pages.
Ideally you want your pages to have as few errors as possible, but even some of the most well-known websites don't
Just remember: Web standards are not strict rules. They are more like guidelines. Validation is a tool to help you pro-
duce better websites; it should never limit you.
All Browsers Are Not Created Equal
In an ideal world, you would be able to code a website and have it behave the same in all web browsers. Sadly, this
is not the case. Cross-browser compatibility is an issue that all web developers have to tackle regularly, and often it
can be a real pain and lead you to spending hours trying to work around a bug that is present in a browser.