For more complex customizations, you can create custom DITA-OT plug-ins that bundle custom fonts, JavaScript, and stylesheets; modify the HTML markup, or override other aspects of HTML processing. HTMLcustom plug-in HTMLfonts HTMLJavaScript HTMLCSS HTMLmarkup, adding CSSHTML fontsHTML These examples are not intended to be used as-is, but illustrate basic techniques you can use in your own plug-ins. In practise, custom plug-ins often combine several of these approaches.