Processing instructions

Overview of processing instructions for styling text at specific points in a book

Processing instructions are pieces of coding that you add to XML markup to change styles or formatting at specific points in a document. This type of XML markup is different from stylesheet features, which are used to change styles throughout a whole document.

There are two stylesheets that contain examples of processing instructions for ebook formats:

These stylesheets are for reference only—you do not set any stylesheet features in either of these. The stylesheets contain examples of how to put processing instructions into XML markup and the values that can be used. Some processing instructions are standard for DocBook XML—those have the prefix dbfo or dbhtml. Other processing instructions were developed specifically for the cop-e-boox stylesheets.

Note: Processing instructions do not work inside <biblioentry> or <bibliomixed> elements. Instead, you will need to insert the relevant Unicode values for processing instructions—those Unicode characters are shown in the two reference stylesheets listed above. Also refer to Common problems for processing instructions in EPUB and web pages.

Specific processing instructions are described in the following sections for PDF ebooks, and EPUB and web ebooks.