Introduction to Composite Capabilities / Preferences Profile (CC/PP)

CC/PP stands for Composite Capabilities/Preferences Profile, and is a system for expressing device capabilities and user preferences. With CC/PP, a user with a specific preference, or disability-related need can clarify that even though their browser handles millions of colours, they personally can only distinguish certain colours. Or, perhaps the user navigates exclusively with a keyboard or stylus.

Why do we need CC/PP?

With the growing popularity of ubiquitous Web devices spread across such a broad range of media and bandwidth, authoring for the Web can sometimes look like a very difficult equation to solve: how can a Web author provide cool multimedia Web content, while keeping that content small and simple enough for very basic devices?

Managing multiple devices is not a new problem, and even though the rapid growth of Web appliances beyond the familiar Web browser makes the challenge especially acute, a few solutions have been developed over the years.

Most of these solutions are based on content selection: the content is given in several equivalent variants, or has mechanisms to define alternative behaviour. Then, at the time the resource is served, either the server chooses which variant is most suitable, or the user agent decides what to do with the choices it is given.

This is easily achieved because user agents identify themselves to servers and scripting languages, and through specific features included in Web document languages:

• Server-driven content negotiation, as defined by HTTP,
• On-the-fly content selection and presentation based on user agent detection, using scripting languages,
• HTML object and link elements have mechanisms defining alternate behaviours,
• SMIL (pronounced “smile”), the multimedia language for audio/visual content, has a switch element defining alternate elements to chose from, and can be used, for example, to choose some content based on available bandwidth,
• CSS also has such a mechanism called Media Queries for selecting appropriate style sheets.

Read more on the shortcomings of current methods on Web Standards