Creating an accessible web site is a very exacting task. Accessibility code changes often because of continuous technology changes. It is very difficult to create an aesthetically pleasing site that also complies with the W3C International guidelines.
There are many different levels of Accessibility – the DCLS site complies with WCAG 2.0 (Level AA)
If you click on the WCAG 2.0 (Level AA) link and submit the site for checking you will see that the DCLS site gets the Green ‘Congratulations! No known problems‘ message. This is very hard to achieve.
You will notice that there are zero ‘Likey Problems‘ but many ‘Potential Problems‘.
Potential problems include things which W3C cannot check automatically – the human eye needs to make that evaluation (such as whether you used colour only to explain something – this would be a problem for colour blind people). So items under this category will still be flagged for checking even if your site fully complies.
Compliance for this site will need to be checked periodically because of the nature of continually changing technology.