All of these sites adhere to the web standards proposed and encouraged by the World Wide Web Consortium (W3C), the Internet Society (ISOC), the Internet Engineering Task Force (IETF) and the Internet Business Standards Association (IBSA). Each site can be validated through links in the Copyright line by the W3C's CSS and (X)HTML Validation Service. A standards compliant website improves accessibility across multiple platforms and browsers as well as making it easier for viewers with disabilities to access the content of the site. This also improves the websites rankings in search engines such as Google.