CSS Mobile Profile 2.0

    Title: CSS Mobile Profile 2.0
    Shortname: css-mobile
    Group: csswg
    Level:
    Status: ED
    Work status: abandoned
    TR: https://www.w3.org/TR/css-mobile/
    ED: https://drafts.csswg.org/css-mobile/
    Previous version: https://www.w3.org/TR/2014/NOTE-css-mobile-20141014/
    Editor: Bert Bos, W3C, bert@w3.org, w3cid 3343
    !Previous editors: Svante Schubert, Sun Microsystems Inc.
    !Previous editors: Robin Berjon, Expway
    Default Biblio Status: snapshot
    Abstract:
      This specification defines in general a subset of CSS 2.1 [[!CSS21]] that is
      to be considered a baseline for interoperability between
      implementations of CSS on constrained devices (e.g. mobile phones).
      Its intent is not to produce a profile of CSS incompatible with the
      complete specification, but rather to ensure that implementations
      that due to platform limitations cannot support the entire
      specification implement a common subset that is interoperable not
      only amongst constrained implementations but also with complete
      ones. Additionally, this specification aligns itself as much as
      possible with the OMA Wireless CSS 1.1 [[WCSS11]] specification. At the same
      time, OMA is doing
      alignment work in OMA Wireless CSS 1.2 [[WCSS12]]. It is aimed at aligning the
      mandatory compliance items between CSS Mobile Profile 2.0 and OMA Wireless CSS 1.2 [[WCSS12]].

      This profile is obsolete. Please see the latest
      CSS Snapshot for the
      specifications that make up CSS.
    Status text:
      At this time, the CSS Working Group does not envisage further
      work on this specification and does not plan to propose it as a W3C
      Recommendation.

## Introduction

This document specifies a profile of CSS that is in general based on CSS 2.1 [[!CSS21]], but requires as well new features from CSS 3. In addition the document defines an OPTIONAL feature set, that is suggested to be implemented by more advanced user agents.

## Conformance

The key words of descriptive assertions and RFC 2119 terminology. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [[!RFC2119]].

Since the goal of this specification is to define a baseline interoperability level, user agents MAY accept CSS documents conforming to CSS 2.1 or subsequent revisions of the CSS family of Recommendations.

In order to conform to this specification, user agents, authoring tools, and content MUST conform to the Conformance and Error conditions section of the CSS 2.1 specification [[!CSS21]], with the following modifications.

1. Only features marked as supported in this specification are REQUIRED. Aside of the REQUIRED feature set, an additional OPTIONAL feature set is given, that may be implemented by more advanced user agents. This feature set is REQUIRED by the CDF as in [[!WICDMobile10]]. Support for a larger set of CSS 2.1 is OPTIONAL.
2. The requirement concerning which CSS 2.1 media types are supported is tightened so that both the `handheld` and `all` media types MUST be accepted and processed. Other media types MAY be accepted and processed as well.
3. The requirements that user agents MUST make it possible to select an alternate style sheet amongst those linked from the document, as well as provide for a way to turn off author style sheets, are relaxed to be RECOMMENDED behavior, but not REQUIRED.

## Selectors

Selectors are defined in the Selectors chapter of the CSS 2.1 specification [[!CSS21]]. The following table identifies which selector constructs MUST be supported amongst those defined by CSS 2.1.

Selector type | Example | Meaning | Conformance
--- | --- | --- | ---
Universal selector | `*` | Matches any element. | REQUIRED
Type selectors | `E` | Matches any E element. | REQUIRED
Descendant selectors | `E F` | Matches any F element that is a descendant of an E element. | REQUIRED
Child selectors | `E > F` | Matches any F element that is a child of an element E. | REQUIRED
The link pseudo-classes | `E:link` | Matches element E if E is the source anchor of a hyperlink, unvisited by a user. | REQUIRED
The link pseudo-classes | `E:visited` | Matches element E if E is the source anchor of a hyperlink, visited by a user. | REQUIRED
The dynamic pseudo-classes | `E:active` | Matches element E if E is being activated by the user. | REQUIRED
The dynamic pseudo-classes | `E:focus` | Matches element E if E has the focus (accepts keyboard events or other forms of text input). | REQUIRED
Class selectors | `.warning` | Language specific. (In (X)HTML, matches elements whose `class` attribute contains a token with the same name.) | REQUIRED
ID selectors | `#myid` | Matches any element with an ID equal to "myid". | REQUIRED
Grouping | `E1, E2, E3 { ... }` | Matches a group of elements, which share the same style declarations. | REQUIRED

## At-rules

At-rules are defined in the at-rules section of the CSS 2.1 specification [[!CSS21]]. The following table identifies which at-rule constructs MUST be supported amongst those defined by CSS by setting the at-rule as REQUIRED in the table's last column. Only at-rules that are part of the suggested feature set for advanced user agents are listed here as OPTIONAL.

Rule | Definition | Conformance
--- | --- | ---
@charset | Defines character encoding for the style sheet. | REQUIRED
@import | Imports an external style sheet. | REQUIRED
@media | Groups a set of style rules to apply only to one or more particular media. Only the `handheld` and `all` media types MUST be accepted and processed. Other media types MAY be accepted and processed as well. | REQUIRED
@namespace | For declaring the default namespace and binding namespaces to namespace prefixes. | OPTIONAL

## Properties

Properties are defined in several chapters of the CSS 2.1 specification [[!CSS21]] and in case of marquee properties in the CSS Marquee Module [[!CSS3MARQUEE]]. The following table identifies which properties MUST be supported amongst those defined by CSS by setting the property as REQUIRED in the table's last column. Only properties that are part of the suggested feature set for advanced user agents are listed here as OPTIONAL. The property syntax is provided (expressed using the same value specifications as CSS 2.1) when it is subsetted from the original. Limitations that apply to a property apply equally to its shorthand alternative.

Property | Syntax (if different from CSS) | Conformance
--- | --- | ---
background-color |  | REQUIRED
background-image |  | REQUIRED
background-repeat |  | REQUIRED
background-attachment |  | REQUIRED
background-position | `top | center | bottom | left | right | inherit` | REQUIRED
background |  | REQUIRED
border-top-width border-right-width border-bottom-width border-left-width |  | REQUIRED
border-width |  | REQUIRED
border-top-color border-right-color border-bottom-color border-left-color |  | REQUIRED
border-color |  | REQUIRED
border-top-style border-right-style border-bottom-style border-left-style | `none | solid | dashed | dotted | inherit` | REQUIRED
border-style | `none | solid | dashed | dotted | inherit` | REQUIRED
border-top border-right border-bottom border-left |  | REQUIRED
border |  | REQUIRED
bottom |  | OPTIONAL
clear |  | REQUIRED
color |  | REQUIRED
display | `inline | block | list-item | none | inherit` | REQUIRED
float |  | REQUIRED
font-family |  | REQUIRED
font-style |  | REQUIRED
font-variant |  | REQUIRED
font-weight |  | REQUIRED
font-size | `<absolute-size> | <relative-size> | inherit` | REQUIRED
font |  | REQUIRED
height |  | REQUIRED
left |  | OPTIONAL
list-style-type | `disc | circle | square | decimal | lower-roman | upper-roman | lower-alpha | upper-alpha | none | inherit` | REQUIRED
list-style-image |  | REQUIRED
list-style |  | REQUIRED
margin-top margin-right margin-bottom margin-left |  | REQUIRED
margin |  | REQUIRED
marquee-direction [[!CSS3MARQUEE]] |  | REQUIRED
marquee-loop [[!CSS3MARQUEE]] |  | REQUIRED
marquee-speed [[!CSS3MARQUEE]] |  | REQUIRED
marquee-style [[!CSS3MARQUEE]] |  | REQUIRED
max-height |  | REQUIRED
max-width |  | REQUIRED
min-height |  | REQUIRED
min-width |  | REQUIRED
outline-color |  | OPTIONAL
outline-style | `none | solid | dashed | dotted | inherit` | OPTIONAL
outline-width |  | OPTIONAL
outline |  | OPTIONAL
overflow [[!CSS21]] | auto | REQUIRED
overflow-style [[!CSS3MARQUEE]] | marquee | REQUIRED
padding-top padding-right padding-bottom padding-left |  | REQUIRED
padding |  | REQUIRED
position |  | OPTIONAL
right |  | OPTIONAL
text-indent |  | REQUIRED
text-align |  | REQUIRED
text-decoration | `none | blink |underline | inherit` | REQUIRED
text-transform |  | REQUIRED
top |  | OPTIONAL
vertical-align | `top | middle | bottom | baseline | inherit` | REQUIRED
visibility |  | REQUIRED
white-space |  | REQUIRED
width |  | REQUIRED
z-index |  | OPTIONAL

### Informative Notes

- Content Providers will reach a larger and more satisfied audience by following Mobile Web Best Practices [[MOBILE-BP]] and CSS Techniques for Web Content Accessibility Guidelines [[WCAG10-CSS-TECHS]].
- The OMA Wireless CSS 1.1 [[WCSS11]] introduced three extensions `Marquee`, `Access Keys` and `Input`. Those extensions are deprecated in OMA Wireless CSS 1.2 [[WCSS12]]. The `Marquee` functionality has been redefined by the marquee properties of the CSS 3 box model [[!CSS3MARQUEE]]

## Syntax

A user agent MUST support all value types defined in the Values section of the CSS 2.1 specification [[!CSS21]], with the following exceptions:

1. Support for counter values is OPTIONAL
2. Support for CSS2 System Colors and User preferences for fonts is OPTIONAL.

## Acknowledgments

The editors wish to thank the authors of the previous version of this document, Ted Wugofski (Openwave), Doug Dominiak (Openwave, formerly Motorola), Peter Stark (Ericsson), and Tapas Roy (Openwave), as well as the authors of the OMA Wireless CSS specifications and the CSS 2.1 specification. Furthermore, the editors want to thank the CDF WG for their participation on this specification.