The new Java Plug-In supports cross-platform specification of JVM command-line arguments to a particular applet via a new parameter to the applet, object and embed tags:

  <PARAM name="java_arguments" value="-Xmx128m -Dsun.java2d.noddraw=true">

The value may be any set of valid JVM command-line arguments. The security implications for this command-line argument specification are similar to those already faced by Java Web Start.

This functionality needs to be documented publicly. Note that this capability does not imply the same level of specification as a public API; it is more of an implementation detail, similar to "codebase_lookup", which is documented at http://java.sun.com/javase/6/docs/technotes/guides/plugin/developer_guide/special_attributes.html .

Engineering specification for feature:

http://j2se.sfbay.sun.com/web/bin/view/Deployment/NewPlugInJavaArgumentsSpec