Processing instructionsProcessing instructions (PIs) are written into the xml when the desired output cannot be
achieved with DocBook elements and attributes alone. PIs may also be used to force special
formatting in only part of a document. For a more technical introduction see Bob Stayton's
DocBook
XSL: The Complete Guide. There are also lists of DocBook-specific processing
instructions for html and pdf output.PIs should be used sparingly: it is easier to maintain documents that achieve the desired
output with DocBook elements and stylesheet parameters. However, there are a few cases where PIs may be
necessary:Force line breakLine breaks should not be used for spacing between elements; this is much
better done with CSS and XSL. Hoever, if entering multiple lines that must be
displayed in succession but without the separation of a new paragraph, you may
use the linebreak PI. The following code
First line Second line Third line]]>
Will outputFirst line Second line Third lineThis only works if
custom stylesheets include the following code, described in Bob Stayton's
DocBook XSL. Sitka's customization layer includes this template as of June
30, 2010:
]]>
Include external contentTo insert external content into the html output use the dbhtml-include processing instruction as described in DocBook XSL.
This could be used to add a custom search box to the title page, an animated tutorial in the relevant section, or any other content in valid xhtml.