A metadata vocabulary for self- and third-party labeling of health web-sites: Health Information Disclosure, Description and Evaluation Language (HIDDEL).

We describe HIDDEL (Health Information Disclosure, Description and Evaluation Language), formerly known as medPICS (platform for Internet content selection in medicine), a metadata vocabulary designed to enhance transparency, trust and quality of health information on the web. The vocabulary may be used (1) by webmasters to self-describe their contents and policies; (2) by infomediaries (e.g. Healthfinder, NHS Direct/NeLH), e.g. third party evaluators, rating or portal services, to annotate other websites; (3) and by users, to describe their preferences. As an XML application it conforms to the W3C's RDF Specification. The metadata vocabulary is primarily intended to enable descriptions of whole health websites or health information providers. The vocabulary is designed to provide a computer-readable electronic "label" of a health website, telling users who is behind the website, how the website is sponsored, what the con-tent, aim and target audience is, how the information was compiled, what risks the service bears, or what people say about the resource. Client-software can "read" this label automatically, compare it to the user s own set of preferences and needs, and alert and advise users.