CC/PP And You: What It's All About

As promised, here's a copy of the CC/PP activity summary that
ran in the 10 October issue of the HTML Writers Guild's newsletter:


What is CC/PP?

CC/PP stands for Composite Capabilities/Preferences Profiles, and
is a way to specify what exactly a user agent (web browser) is
capable of doing.  This allows for sophisticated content 
negotiation techniques between web servers and clients, to produce
optimized XML-based markup for display and use on a wide variety
of web user agents.


But What _Is_ It?

In technical terms, CC/PP is an RDF-based framework for describing
and managing software and hardware profiles that include information
on the user agent's capabilities (physical and programmatic); the
user's specified preferences within the user agent's set of options;
and specific qualities about the user agent that can affect content
processing and display, such as physical location.

CC/PP is designed to work with a wide variety of web-enabled devices,
from PDAs to desktop machines to laptops to WAP phones to phone
browsers to web television units to specialized browsers for users
with disabilities.  Proxies may also be used to provide markup
transformation, transmission, or caching services for CC/PP-enabled
clients and servers.

The CC/PP framework provides a way to describe generic profiles
accessible via the web -- for example, from the hardware or software
vendor -- reducing the amount of information that must be directly
sent from the user agent itself (or a proxy), an important consideration
for limited-bandwidth cellular modem technologies.


How Will It Be Used?

CC/PP is simply the language for describing what the user agent
can (currently) do.  This information would then be conveyed to
the originating server as part of an HTTP (or other protocol)
request, and it's up to the server to decide how to use the user
agent profile to best meet the needs of the user agent client.
The two primary ways in which a profile might be used are
_selection_ and _transformation_.

Selection is the process by which the originating server chooses
an appropriate representation of requested web content from a
finite set of existing representations.  For example, the site might
have three versions of a given page:  a "rich XHTML with Java and
ECMAscript" version for visual browsers, a "textual XHTML" version
for non-visual browsers and older browsers, and a WML version for
WAP phones.  From the capabilities and preferences described in the
CC/PP profile, the server would select the best match and send that
back to the user agent.

Transformation, on the other hand, assumes that there is no finite set
of representations, but rather than content is created on the fly,
based on the properties expressed by the user agent profile.  The
content would be stored in an XML-compatible format and then
transformed into an appropriate language (or modules thereof) that
could be understood and optimized for the user agent, such as XHTML
or WML.

CC/PP-based content transformations require a strong understanding
of what is contained within a document and how best to transform 
the content for various user agent capabilities and preferences;
for this reason, the CC/PP Working Group is watching the XHTML
modularization process and the (X)HTML Working Group's document
profiles.

The CC/PP approach to preferences and capabilities is superior to
the presently used methods of simple browser detection because it
provides a framework that is not dependent upon recognizing a
particular browser type and inferring capabilities, but deals
directly with the properties of the user agent and the current
settings employed.


About the W3C's CC/PP Working Group

The CC/PP Working Group was chartered in summer of 1999 and is an
outgrowth of the W3C's Mobile Access Interest Group.  The first
face to face meeting was held in Stockholm, Sweden, on the 23rd
and 24th of September, and was hosted by Ericsson.  Johan Hjelm
of the W3C (and Ericsson) is the chair of the Working Group.

Companies and organizations currently participating in the CC/PP
working group include:

* Ericsson                             * Nokia
* Fujitsu Laboratories                 * Nortel Networks
* HTML Writers Guild                   * SAP AG
* IBM                                  * SBC Technology Resources
* IETF                                 * Sun
* Interleaf                            * T-Mobil
* Matsushita Electric Industrial Co.


For More Information

To learn more about CC/PP, you can visit the CC/PP homepage at:

       http://www.w3.org/Mobile/CCPP/

Further details on the HWG's involvement in the W3C can be found
on the Guild's website at:

       http://www.hwg.org/opcenter/w3c/


-- 
Kynn Bartlett  <kynn@idyllmtn.com>                   http://www.kynn.com/
Chief Technologist, Idyll Mountain Internet      http://www.idyllmtn.com/
Catch the Web Accessibility Meme!                   http://aware.hwg.org/
Seeking the Best Internet Dog of 1999!     http://www.virtualdogshow.com/

Received on Saturday, 30 October 1999 03:59:55 UTC