Skip to Main Content
Webmaster in a Nutshell, Third Edition
book

Webmaster in a Nutshell, Third Edition

by Robert Eckstein, Stephen Spainhour
December 2002
Intermediate to advanced content levelIntermediate to advanced
576 pages
32h
English
O'Reilly Media, Inc.
Content preview from Webmaster in a Nutshell, Third Edition

Document Type Definitions

A DTD specifies how elements inside an XML document should relate to each other. It also provides grammar rules for the document and each of its elements. A document adhering to the XML specifications and the rules outlined by its DTD is considered to be valid. (Don’t confuse this with a well-formed document, which adheres only to the XML syntax rules outlined earlier.)

Element Declarations

You must declare each of the elements that appear inside your XML document within your DTD. You can do so with the <!ELEMENT> declaration, which uses this format:

<!ELEMENT elementname rule>

This declares an XML element and an associated rule called a content model, which relates the element logically to the XML document. The element name should not include <> characters. An element name must start with a letter or an underscore. After that, it can have any number of letters, numbers, hyphens, periods, or underscores in its name. Element names may not start with the string xml in any variation of upper- or lowercase. You can use a colon in element names only if you use namespaces; otherwise, it is forbidden.

ANY and PCDATA

The simplest element declaration states that between the opening and closing tags of the element, anything can appear:

<!ELEMENT library ANY>

The ANY keyword allows you to include other valid tags and general character data within the element. However, you may want to specify a situation where you want only general characters to appear. This type of data ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Webmaster in a Nutshell, Second Edition

Webmaster in a Nutshell, Second Edition

Stephen Spainhour, Robert Eckstein

Publisher Resources

ISBN: 0596003579Purchase bookErrata Page