I'm using IDEA 4.5. In previous versions I was able to define additional JavaDoc tags, e.g. for EJBGen. However, in 4.5 I don't know where to add these tags. Perhaps it's Friday and I'm braindead, but I can't find this under any of the settings. My config\options\editor.codeinsight.xml file contains an entry:
<option name="ADDITIONAL_JAVADOC_TAGS" value="ejbgen:session,....