4 Chapter 1
Before a document can progress from a Working Draft, its status
changes to Last Call, which means the review period is about to close and
usually indicates the document is ready to progress to the next level.
That next level is Candidate Recommendation, which means the W3C is
satisfied the document makes sense, the latest reviews have found no sig-
nificant problems, and all technical requirements have been satisfied. At
this point, browser makers may begin to implement the properties in the
document to gather real-world feedback.
When two or more browsers have implemented the properties in the
same way and if no serious technical issues have come to light, the docu-
ment may progress to being a Proposed Recommendation. This status means
the proposal is now mature and implemented and ready to be endorsed
by the W3C Advisory Committee. When this endorsement has been
granted, the proposal becomes a Recommendation.
To reiterate what I briefly touched on before, the recommendation
process and the implementation process do not always work in the same
way. A module can be well-implemented across all browsers, yet still hold
Working Draft status—as I write this, the Transitions module (Chapter 14)
has exactly that status. Conversely, a module may hold Candidate Recom-
mendation status yet have only limited implementation—CSS Shapes
(Chapter 19) fits this description right now.
As a result, I’ve written this book in a loose order of implementation,
rather than based on recommendation status. Earlier chapters discuss
features that have full implementation across all browsers (or should by
the time this book is released); later chapters cover features that are imple-
mented in some browsers only—often with browser-specific prefixes; and
chapters toward the end of the book deal with potential, speculative, or
partial implementations of properties.Introducing the Syntax
With the introductions and explanations out of the way, let’s get to the meat
of CSS3. Throughout this book, I use a certain syntactical convention to dem-
onstrate each of the new rules and properties. It looks something like this:E { property: value; }In this code example, the selector is represented with E. Of course, in
HTML, this selector doesn’t exist; I’m merely using it to indicate the selec-
tor is irrelevant; any selector could be used here.
Next, you have the property itself; in this case, I’ve used a made-up
property, called property. Following this is the value of the property. For
this, I use an italicized alias to refer to the value, which in this case I’ve
called value.
If a property accepts multiple values, I’ll list each with a unique alias.
So a new property that requires three values might be defined like this:E { property: first second third; }