9.3. Writing and translation the CLIP documentation.

Structural Elements

<book>

The book is the most common toplevel element, and is probably the one you should use for your document.

<set>

If you want to group more than one book into a single unit, you can place them all inside a set. This is useful when you want to bundle up documentation in alternate ways. We do this with the documentation, using a <set> to put everything into a single directory, and a <book> to put each Wine guide into a separate directory.

<chapter>

A <chapter> element includes a single entire chapter of the book.

<part>

If the chapters in your book fall into major categories or groupings, you can place each collection of chapters into a <part> element.

<sect?>

DocBook has many section elements to divide the contents of a chapter into smaller chunks. The encouraged approach is to use the numbered section tags, <sect1>, <sect2>, <sect3>, <sect4>, and <sect5> (if necessary). These tags must be nested in order: you can't place a <sect3> directly inside a <sect1>. You have to nest the <sect3> inside a <sect2>, and so forth. Documents with these explicit section groupings are easier for SGML processors to deal with, and lead to better organized documents. DocBook also supplies a <section> element which you can nest inside itself, but its use is discouraged in favor of the numbered section tags.

<title>

The title of a book, chapter, part, section, etc. In most of the major structural elements, like <chapter>, <part>, and the various section tags, <title> is mandatory. In other elements like <book> and <note>, it's optional.

<para>

The basic unit of text is the paragraph, represented by the <para> tag. This is probably the tag you'll use most often. In fact, in a simple document, you can probably get away with using only <book>, <chapter>, <title>, and <para>.

<article>

For shorter, more targeted documents, like topic pieces and whitepapers, you can use <article> as your toplevel element.

Inline Formatting Elements

<filename>

The name of a file. You can optionally set the class attribute to Directory, HeaderFile, and SymLink to further classify the filename.

<userinput>

Literal text entered by the user.

<computeroutput>

Literal text output by the computer.

<literal>

A catch-all element for literal computer data. Its use is somewhat vague; try to use a more specific tag if possible, like <userinput> or <computeroutput>.

<quote>

An inline quotation. This tag typically inserts quotation marks for you, so you would write <quote>This is a quote</quote> rather than "This is a quote". This usage may be a little bulkier, but it does allow for automated formatting of all quoted material in the document. Thus, if you wanted all quotations to appear in italic, you could make the change once in your stylesheet, rather than doing a search and replace throughout the document. For larger chunks of quoted text, you can use <blockquote>.

<note>

Insert a side note for the reader. By default, the SGML processor usually prefixes the content with "Note:". You can change this text by adding a <title> element. Thus, to add a visible FIXME comment to the documentation, you might write:

<note>
  <title>FIXME</title>
  <para>This section needs more info about...</para>
</note>

The results will look something like this:

	FIXME
	This section needs more info about...

<sgmltag>

Used for inserting SGML tags, etc., into a SGML document without resorting to a lot of entity quoting, e.g., &lt;. You can change the appearance of the text with the class attribute. Some common values of this are starttag, endtag, attribute, attvalue, and even sgmlcomment. See this SGML file, documentation/documentation.sgml, for examples.

<prompt>

The text used for a computer prompt, for example a shell prompt, or command-line application prompt.

<replaceable>

Meta-text that should be replaced by the user, not typed in literally, e.g., in command descriptions and --help outputs.

<constant>

A programming constant, e.g., MAX_PATH.

<symbol>

A symbolic value replaced, for example, by a pre-processor. This applies primarily to C macros, but may have other uses. Use the <constant> tag instead of <symbol> where appropriate.

<function>

A programming function name.

<parameter>

Programming language parameters you pass with a function.

<option>

Parameters you pass to a command-line executable.

<varname>

Variable name, typically in a programming language.

<type>

Programming language types, e.g., from a typedef definition. May have other uses, too.

<structname>

The name of a C-language struct declaration, e.g., sockaddr.

<structfield>

A field inside a C struct.

<command>

An executable binary, e.g., /bin/sh or ls.

<envar>

An environment variable, e.g, $PATH.

<systemitem>

A generic catch-all for system-related things, like OS names, computer names, system resources, etc.

<email>

An email address. The SGML processor will typically add extra formatting characters, and even a mailto: link for HTML pages. Usage: <email>user@host.com</email>

<firstterm>

Special emphasis for introducing a new term. Can also be linked to a <glossary> entry, if desired.

Item Listing Elements

<itemizedlist>

For bulleted lists, no numbering. You can tweak the layout with SGML attributes.

<orderedlist>

A numbered list; the SGML processor will insert the numbers for you. You can suggest numbering styles with the numeration attribute.

<simplelist>

A very simple list of items, often inlined. Control the layout with the type attribute.

<variablelist>

A list of terms with definitions or descriptions, like this very list!

Block Text Quoting Elements

<programlisting>

Quote a block of source code. Typically highlighted in the output and set off from normal text.

<screen>

Quote a block of visible computer output, like the output of a command or chunks of debug logs.

Hyperlink Elements

<link>

Generic hypertext link, used for pointing to other sections within the current document. You supply the visible text for the link, plus the name of the id attribute of the element that you want to link to. For example:

<link linkend="configuring">the section on configuring wine</link>
...
<sect2 id="configuring">
...

<xref>

In-document hyperlink that can generate its own text. Similar to the <link> tag, you use the linkend attribute to specify which target element you want to jump to:

<xref linkend="configuring">
...
<sect2 id="configuring">
...

By default, most SGML processors will autogenerate some generic text for the <xref> link, like "Section 2.3.1". You can use the endterm attribute to grab the visible text content of the hyperlink from another element:

<xref linkend="configuring" endterm="config-title">
...
<sect2 id="configuring">
  <title id="config-title">Configuring</title>
...

This would create a link to the configuring element, displaying the text of the config-title element for the hyperlink. Most often, you'll add an id attribute to the <title> of the section you're linking to, as above, in which case the SGML processor will use the target's title text for the link text.

Alternatively, you can use an xreflabel attribute in the target element tag to specify the link text:

<sect1 id="configuring" xreflabel="Configuring">

<xref> is an empty element. You don't need a closing tag for it (this is defined in the DTD). In SGML documents, you should use the form <xref>, while in XML documents you should use <xref/>.

<anchor>

An invisible tag, used for inserting id attributes into a document to link to arbitrary places (i.e., when it's not close enough to link to the top of an element).

<ulink>

Hyperlink in URL form, e.g., http://www.itk.ru.

<olink>

Indirect hyperlink; can be used for linking to external documents. Not often used in practice.