As with any skill that you do not use on a daily basis, your knowledge of the details is going to fade. This is especially true of technologies like XML that have lots of syntactical quirks that are easy to forget. This is where XML in a Nutshell comes in. Like all O’Reilly Nutshell books it does an excellent job of cramming all of the little facts needed to work with XML into a concise easy to reference book. <div style="clear: left"> </div>
But, like all Nutshell books, this is not a tutorial! You need to know what you are doing with XML and why you are using XML before it will be of much help to you.
The book itself is divided into 4 sections.
First an overview is given of the basic concepts to help you brush up on the fundamentals. This covers the basics of XML formatting, entities, DTDs, namespaces and how to deal with non-US character sets.
The second section covers what the authors refer to as Narrative Centric Documents. I would better describe this as methods of using XML that relate to presentation of data. This covers XHTML (and it’s helper CSS), and XSL (and it’s helpers XSLT, XPATH, XLINKS, etc).
The third section covers using XML as a data storage format (which can then be presented using the technologies in section 2). It also covers the technology and methodologies used to access XML documents; SAX and DOM.
The forth section is a reference to all of the syntax and formatting issues that you need to know to generate valid forms of the technologies discussed.
If you need to learn XML and what it can be used for, this is probably not your book, but if you need to look up the attributes for the xsl:output tag, this is what you need.