This site has been designed with the aim of presenting responsive, easily navigable pages to as many users as possible, but presumes visitors are using at least a level 3 browser with images enabled and a connection speed close to or better than 33kbps. The appearance of the pages is managed using a single cascading style sheet linked to each page. A page should still display legibly (albeit differently) if the style sheet is disabled. The total page size, including all the embedded elements, should be less than 40k, and leading pages should be smaller than 20k. Embedded graphics are optimized for screen display at 72dpi and re-sampled to minimize their file size. As a matter of policy the site does not use pages with frames, which present difficulties for search engines and make printing, bookmarking, linking, and 'back' or 'forward' browser navigation unpredictable. Standard link colours for hypertext links are being retained.