Définitions courantes en CSS.

The status.

The status indicates the position of the W3C in relation to the property.

• Standard : The property is standardized and commonly recognized by major current browsers. It can be used without concern.
  By major browsers, we mean Chrome  , Edge  , Firefox  , Opera  , Safari   on PC or mobile, and Samsung Internet   and Samsung Internet   on mobile.
  The Internet Explorer   browser is practically no longer used, and other browsers are marginal.
• Experimental ⚠ : The property displays numerous malfunctions on several major browsers. In general, it is a recent property that has not yet been implemented.
  It is sometimes recognized under its proprietary name (prefixed with -webkit- or -mozilla-).
• Obsolete ✗ : The property is no longer or is not standardized by the W3C. This does not mean that no browsers recognize it.
  However, it is strongly advised not to use these properties in style sheets.

Predefined values.

The list of predefined values accepted by the property. Each of these values corresponds to a keyword defined in the language. In some cases, these keywords are associated with a dimension, a color, etc.; for example, color names are associated with the color code. In other cases, these names are not associated with any numeric value: the values for border-style, for example.

A property that accepts predefined values can also accept dimension, color, values.

Initial value.

Each property has an initial value: the value of the property when it is neither set nor inherited from any rule. This value is standardized by the W3C.

Animation types.

Reminder: an animation consists of gradually changing the value of a property. This change can be interrupted at any time, it can run once, multiple times, or an infinite number of times. Not all properties can be animated; some, such as the properties that define animations, cannot be animated. In the summary tables, the type of animation indicates how the property can be animated, and whether it can be animated at all.

• Not animable: The property cannot be animated. In general, this is due to the complexity or nonsense it would create. For example, properties that define animations cannot themselves be animated.
• Discrete: The property changes value automatically, but this happens abruptly, without any transition. Properties that only accept non-numeric predefined values (such as font-family) will switch abruptly from one value to another.
• By computed value: The transition between the different values occurs gradually. As a general rule, properties that accept numeric values or colors can be animated in this way.
• Repeatable list: behaves like by computed value with lists of values.
• Integer: This is a variant of the discrete type. It concerns properties that only accept integer values. Although numeric, these values cannot change continuously: they jump from one integer to another. This is the case for properties such as z-index, grid-row, grid-column, for example.

Canonical orders.

Some properties accept multiple values, some of which are optional. This is particularly the case for summarized properties. The canonical order indicates the order in which these property values are serialized (stored). Most of the time, it is also the order in which they should be listed.

Example: the property background-size:50px 200px; assigns 50px to the horizontal dimension of the background, and 200px to the vertical dimension. Since these two values have identical formats, they can only be distinguished by their position (the first being the horizontal dimension and the second the vertical dimension). Therefore, the order in which these values are listed is important.

On the other hand, the border property is a shorthand property that expects three values: border width, border style, and border color. These three values have very different formats: the width is a dimension, the style is an enumerated value, and the color is a color. In this case, the values can be listed in any order: the browser will recognize them based on their type.

Here are the possible values for the canonical order:

• Single: this is the case for properties that expect only a single value. There is no concept of order.
• Per grammar : Several values are expected. They are serialized in the order of the syntax.
  They must also be listed in the order of the syntax, even if, in some cases, the browser is able to recognize them based on their type.

Module lifecycle.

Since version 3 of CSS, W3C publishes its specifications in the form of modules. Each module covers a particular theme. For example: fonts, images, grids, etc. Each of these modules has a status, WD, REC, etc.

Each document follows the following process until the recommendation, but they may stop before reaching it, or go back. Likewise, not all recommendations end up obsolete.

First draft publication

Working draft

Candidate recommandation

Proposed recommandation

Recommandation

Deprecated

Module Status.

• FPWD (First Publication of Working Draft).
  First publication of a working draft. This site does not distinguish between FPDW and WD.
• WD (Working Draft).
  This is a document that the W3C has published for review by the community, including W3C members, the public, and other technical organizations. Some of these drafts, but not all, are intended to evolve into a recommendation. Any working draft that is not, or is no longer, intended to evolve into a recommendation should be published as a working group note. Working drafts do not necessarily represent the consensus of the working group and do not imply any endorsement by the W3C or its members beyond the agreement to work on a general technological area.
• CR (Candidate Recommendation).
  A candidate for recommendation is a document that meets the technical requirements of the Working Group that produced it and its dependencies. Candidates for recommendation are expected to be acceptable as recommendations.
• PR (Proposal Recommendation).
  A proposed recommendation document is a document that has been accepted by the W3C as being of sufficient quality to become a recommendation. This phase sets a deadline for the Advisory Committee's review, which begins at the CR stage. Substantial changes should not be made to a proposed recommendation document except in the event of the publication of a new Working Draft or Candidate Recommendation.
• REC (Recommandation).
  A W3C recommendation is a specification or a set of guidelines or requirements that, after broad consensus, has received approval from W3C members. The W3C recommends the widespread deployment of its recommendations as standards for the Web. W3C recommendations are not subject to intellectual property licenses (W3C patent policy). As technology evolves, a recommendation may become obsolete.
• DEPR (Deprecated).
  An Obsolete Recommendation is a specification that the W3C considers to be outdated due to technological developments, for example.

Let's also note these two statuses, which are not part of the life cycle of a document at the W3C:

• NOTE (Working Group Note).
  A working group note is a document that is not intended to become a recommendation, or it is an older WD document whose standardization has been abandoned. Nevertheless, it has the advantage of documenting a technical aspect.
• ED (Editor's DWraft).
  An editor's draft has no official status at the W3C and generally does not represent a consensus of a working group. Its content is not yet approved by the W3C and may never be.