Information on actions returned by AdvisableOperation#getAct

I've found that AdvisableOperation#getActions() returns a String array with each String having the form <ActionPart1>/.../<ActionPartN>. Can someone point me to information on the returned actions such as the possible values for each of action part and their semantics? The Javadoc for AdvisableOperation#getActions() implies that the actions are defined by subclasses of AdvisableOperation. However, looking at the Javadoc for WorkItemProcessAreaOperation#getActions(), for example, I find no additional information.

Thanks,
Geoff Alexander