Different ways to use browser and system media resources

Question

Examples:

<img src="system://media/icons/logo.png" alt="OS">
<style>
  img.browserIcon {background-image: url(browser://media/icons/logo.png); width: 16px; height: 16px;}
</style>

On Firefox you can access to some resources like this:

<style>
  .button {background: transparent url(chrome://global/skin/button/startcap.png) no-repeat scroll left top}
</style>

Is it possible to access to rasterized font data or system sounds?
e.g. something like url(typeface://arial/d/13px) :)