Im still drafting this section. Please forgive the brevity. The gist of it is this: the presentation and aesthetic value of a website are not the full measure of it's quality. Let the buyer beware! Mark up - the language that describes the structure and data of a webpage - needs to be clean and bear semantic significance. This is important because the disabled rely on intepretation of the markup to gather meaning and importance of the different elements. If your web designer is using tables to layout your web page a blind person will wonder what sort of data set consists of images. You can make a bit of text large and bold, but unless it is appropriately tagged, it wont be clear that it is the title of the following paragraph. Perhaps more importantly, humans are not the only ones reading anymore. Machines will be intepreting your webpage and presenting it on other platforms or in abbridged formats.