One thing that I learned the hard way was grouping multiple packages together. The example (http://maven.apache.org/plugins/maven-javadoc-plugin/examples/group-configuration.html) only shows one package per group, but this could be enhanced. Could you please show the asterisk notation (subpackages) and the separator (colon or semicolon)? By the way, I erroneously tried to use multiple <packages> – which seemed a natural expectation – but it didn't work and was silently ignored. A note to this effect may be useful.