Cascading Style Sheets (CSS) Working Group Charter

The mission of the Cascading Style Sheets (CSS) Working Group, part of the Style Activity, is to develop and maintain CSS.

Join the Cascading Style Sheets (CSS) Working Group.

End date 30 Sep 2013
Confidentiality Proceedings are public
Initial Chairs Daniel Glazman, Peter Linss
Initial Team Contacts
(FTE %: 85)
Chris Lilley, Bert Bos
Usual Meeting Schedule Teleconferences: Weekly
Face-to-face: 3-4 per year


The CSS WG develops the following, somewhat independent technologies:

An example of a language that uses only the syntax is STTS (developed by Disruptive Innovations). An example that uses the syntax, the cascading & inheritance, but not the layout model is the set of properties for styling SVG. CSS levels 1, 2 and 3 include the syntax, cascading & inheritance and rendering model.

CSS is a rather large and complex language. CSS beyond Level 2 is being developed as a set of modules each of which may advance on the W3C Recommendation Track independently. Among them are modules for syntax, cascading and inheritance, and, of course, many aspects of typography, page layout and presentation.

As individual CSS modules advance to REC, the Group periodically publishes a new snapshot of CSS. Each defines the set of CSS modules that are stable at that point.

Profiles are subsets of the features of CSS, usually for a specific kind of device. The CSS WG has published profiles for TV, mobile phones and low-end printers. The number of such profiles should stay as small as possible, but when needed, the working group tries to cooperate with the organizations that need the profiles.

The CSS WG not only develops CSS, but also checks that properties needed by other working groups and which could occur in a style sheet together with CSS properties, are compatible with CSS in general and consistent in their naming schemes. This affects properties such as those of SVG and Device Independence (such as media features), but not properties such as those in STTS nor the presentation attributes of XSL, SVG or DFXP.

Part of the work of the working group is also to develop test suites for the various specifications it publishes.

Another part is to maintain errata and, when needed, publish revised versions of the various specifications.

Success Criteria

The CSS Working Group's work is considered a success if there are multiple independent complete and interoperable implementations of its deliverables that are widely used.


Some modules are expected to become Recommendations in the timeframe of this charter. Others are expected to move to Candidate Recommendation and have test suites developed; or to move to Last Call.


These modules have an active editor, an advocate in the Working group, are under active implementation and are expected to move to Recommendation status within two years.

Candidate Recommendation

These modules have an editor, an advocate in the Working group, are expected to move to CR and have test suites developed within two years.

Working Draft

These modules may be worked on if there is time. They might not currently have an editor.

Joint Work

Items jointly published by CSS and SVG WGs, such as those arising from the FX Task Force Work.

Items jointly published by I18n Core, CSS, XSL and SVG WGs


Maintenance items are W3C Recommendations (or are expected very soon to become Recommendations) which will be maintained by collecting errata and, if needed, by the publication of new editions incorporating those errata.


Completed items are finished, and not considered to require active maintenance.


Discontinued items will no longer be worked on; either because they are superseded by another specification, or because interest has moved on to other areas. In the case of Working Drafts, they may be republished as notes.

Other Deliverables

The Group creates a comprehensive test suite for each CSS module before it becomes Recommendation.

The Group monitors, tracks, and encourages implementation of CSS, both during Candidate Recommendation and afterwards.


Current status of each module, including implementation and testsuite status and other spec dependencies which may block it, is maintained on the CSS Specification page.

Dependencies and Liaisons


Internationalization Activity
The Group coordinates closely with the Internationalization Activity to ensure effective support for internationalization.
Scalable Vector Graphics (SVG) Working Group
The Group coordinates closely with the SVG WG on common features (such as the CSS Animations, CSS Fonts, CSS Object Model, CSS 2D and 3D Transformations, and CSS Transitions Modules) to meet the needs of HTML/CSS, SVG, and mixed HTML/CSS/SVG content, and to ensure compatibility at the functionality level for ease of implementation and authoring. The FX Task Force is the primary venue for this work, and some specifications are published jointly.
XML Print and Page Layout Working Group
The Group tries to harmonize names and behavior of features with the XML Print and Page Layout Working Group.


The following is a list of known liaisons with other W3C groups at the time this charter was written. The group also coordinates with groups not listed here through the Hypertext Coordination Group.

WAI Protocols and Formats Working Group
The Group coordinates closely with WAI PF to ensure effective support for accessibility.
Web Applications Working Group
The Group reviews the Selectors API specification, being developed by the WebApps WG.
WebFonts Working Group
The Group coordinates with the WebFonts WG to enable high quality Web typography with downloadable fonts, in particular WOFF.
The International Digital Publishing Forum (IDPF)
The Group liaises with the IPDF, who develop the EPUB standards for eBooks, to ensure interoperability and convergence between Web and eBooks in the area of styling.

Furthermore, Cascading Style Sheets (CSS) Working Group expects to follow these W3C Recommendations:


To be successful, the group is expected to have 10 or more active participants for its duration. Effective participation is expected to consume one work day per week for each participant; two days per week for editors. The group allocates also the necessary resources for building Test Suites.

Participants are reminded of the Good Standing requirements of the W3C Process.


The Group holds weekly teleconferences, and primarily conducts its work on the public mailing list www-style@w3.org (archive) for technical discussions. A member-only mailing list w3c-css-wg@w3.org (archive) is also available for member-only communications

The list of current members of the CSS WG is public.

Information about the group (deliverables, participants, face-to-face meetings, teleconferences, etc.) is available from the CSS Working Group page and the CSS Working Group wiki.

Decision Policy

As explained in the Process Document (section 3.3), this group seeks to make decisions when there is consensus. When the Chair puts a question and observes dissent, after due consideration of different opinions, the Chair should record a decision (possibly after a formal vote) and any objections, and move on.

When the Chair conducts a formal vote to reach a decision on a substantive technical issue, eligible voters may vote on a proposal one of three ways: for a proposal, against a proposal, or abstain. For the proposal to pass there must be more votes for the proposal than against. In case of a tie, the Chair decides the outcome of the proposal. The Chair must only conduct a formal vote during a group meeting, and at least two-thirds of participants in Good Standing must be in attendance.

Patent Policy

This Working Group operates under the W3C Patent Policy (5 February 2004 Version). To promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis.

For more information about disclosure obligations for this group, please see the W3C Patent Policy Implementation.

About this Charter

This charter for the Cascading Style Sheets (CSS) Working Group has been created according to section 6.2 of the Process Document. In the event of a conflict between this document or the provisions of any charter and the W3C Process, the W3C Process shall take precedence.

Please also see the previous charter for this group.

Per process doc 6.2.3, the most important changes are summarised here.

Daniel Glazman, Peter Linss, Bert Bos, Chris Lilley

$Date: 2012/06/14 12:17:55 $