In addition to the basic modifications that can be made with parameter settings and property files, you can create custom HTML plug-ins that bundle custom fonts, JavaScript, and stylesheets; modify the HTML markup, or override other aspects of HTML processing. HTML custom plug-in HTML fonts HTML JavaScript HTML CSS HTML markup, adding CSS HTML fonts HTML 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.