VMS Help JAVA, Qualifiers, /SYSTEM_PROPERTY  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /SYSTEM_PROPERTY="propertyName=newValue"
       -D propertyName=newValue

    Redefines a property value. The propertyName is the name of the
    property whose value you want to change and newValue is the value
    to change it to. For example, the following command line sets the
    value of the property awt.button.color to "green".

    % java -Dawt.button.color=green ...

    The JAVA command accepts any number of /SYSTEM_PROPERTY
    qualifiers on the command line.