Conventions Used

CSS design is a subset of a wider range of technologies from the World Wide Web Consortium (W3C), collectively referred to as Web standards, which includes HTML, XHTML, and XML. Standards-based design refers to the collective whole, and although not every technology needs to be present in a document, a Web page that conforms to the relevant standards is said to be standards-compliant.

Because HTML and XHTML have much in common and may be used interchangeably, when we refer to HTML it's safe to assume that this also includes XHTML as well, unless specifically noted.

Notes and tips available in the sidebar are meant to correspond to the area within the text that is next to them. Screen shots are displayed in close proximity to the reference within the text.

Specific CSS properties and values will be printed in a monospace font, like this: 12px, font-size, and #summary. References to the concepts themselves will not be formatted; for example, pixel as compared with px, font size as compared with font-size.

An arrrow () within code indicates that the code continues into the next linethere should not be a break in the line.

Browsers are always changing, and any attempt at listing browser support in a book will quickly fall out of date. However, we also get frustrated with books that tell you about advanced techniques but don't tell you that you can't use them in 80 percent of the browsers on the market. So where possible, we've provided real-world browser support advice based on the most commonly used browsers at the time this book was written.

Referring to specific browser versions was a difficult task; when there are four major versions of Microsoft Internet Explorer across two operating systems, and some techniques work in only specific combinations of the four, it's hard to refer to Internet Explorer at all without clarifying in each reference which version we're talking about. To help combat this problem, here is a brief guide to our conventions when talking about Internet Explorer:

• Internet ExplorerAll major versions. This means version 5.0, 5.5, and 6.0 on Windows, as well as 5.2 on Mac OS X. Versions lower than 5.0 are generally unused today and in most cases may safely be ignored.

• Internet Explorer for WindowsAll major versions on Windows. Disregard Mac versions.

• Internet Explorer for MacVersion 5.2 for Mac OS X, and in most cases 5.1 for Mac OS 9. Disregard Windows versions.

• Internet Explorer x.xWhen we refer to a specific version number or multiple version numbers, the other versions not referenced may be disregarded.