Chapter and section numbering

There are several parameters that control numbering of chapter and section titles. By default in printed output, chapter titles are numbered but section titles are not. Appendix titles are numbered (with letters) when in a book, but not numbered by default when in an article. In the DocBook XSL stylesheets, the number part of a title is called a label.

If you prefer to turn off chapter numbering, then set the chapter.autolabel parameter to zero. If you also want to turn off appendix numbering (A, B, C, etc.), then also set the appendix.autolabel parameter to zero.

xsltproc  --output  \
  --stringparam  chapter.autolabel 0 \
  --stringparam  appendix.autolabel 0 \
  fo/docbook.xsl  myfile.xml

To turn on basic section numbering, set the section.autolabel parameter to 1. Then your titles will be numbered as follows:

Chapter 3. Using a mouse
1.  Basic mouse actions    sect1
1.1  Left button           sect2
1.2  Right button          sect2
1.2.1 Context menus        sect3
2.  Selecting              sect1
2.1  Click and drag
2.2  Double click

Notice that the section numbers do not include the chapter number by default, so section numbering starts over with each new chapter. If you prefer the section numbers to include the chapter number, then set the section.label.includes.component.label parameter to 1. This assumes that you leave chapter numbering turned on. For example:

xsltproc  --output  \
  --stringparam  section.autolabel 1 \
  --stringparam  section.label.includes.component.label 1 \
  fo/docbook.xsl  myfile.xml

This results in the following numbering style:

Chapter 3. Using a mouse
3.1.  Basic mouse actions    sect1
3.1.1  Left button           sect2
3.1.2  Right button          sect2 Context menus        sect3
3.2.  Selecting              sect1
3.2.1  Click and drag
3.2.2  Double click

Section labels in an appendix will use the appendix letter instead of a chapter number.

Depth of section numbering

You may want to limit the depth of sections that get a section number. If you have deeply nested sections, then the string of numbers in the section label can get quite long. Or perhaps you just want sections at levels 1 and 2 to be numbered, since any lower level sections aren't important enough to have a number label.

You can use the section.autolabel.max.depth parameter to control which section levels get a number label. If you set the parameter to 2, then only sections at levels 1 and 2 will have the label. The default value is 8, meaning all section levels have numbering (if it is turned on).

Numbering book parts

When producing a book, it is sometimes appropriate to group related chapters into book parts. To do that, you use part elements in your book element, and then put your chapter elements inside your part elements. Each part has a title, and may have a title page to indicate a new grouping of chapters.

Numbering of book parts is turned on by default, using uppercase roman numerals. You can turn off part numbering by setting the part.autolabel parameter to zero.

Regardless of whether parts are numbered, you can restart chapter numbering at the beginning of each part. If you want that type of chapter numbering, set the label.from.part parameter to 1. If you use that option, you will probably also want to set the component.label.includes.part.label parameter to 1. That changes the chapter numbering so the chapters in the first part are numbered I.1, I.2, I.3, etc., and the chapters in the second part are numbered II.1, II.2, II.3, etc. If you don't set the second parameter, then your output will have more than one “Chapter 1” and citations and cross references will be ambiguous. The parameter similarly modifies appendix numbers.

If you would rather number your parts using arabic numerals instead of uppercase roman numerals, you can't do it with a stylesheet parameter. You have to customize a template in a customization layer. Although customizations are covered later, this one is included here to make it easier to find.

<xsl:template match="part" mode="division.number">
  <xsl:number from="book" count="part" format="1."/>