Took out the stars because nowhere else in the document were they used in this manner (as a kind of metadata tag). I struggled a bit with this one, but reasoned as follows:

* The four inverse functional identifiers have already been listed under 4.1.2.1 'Description'.  
* Together with the description of Actor our most likely reader group (trained programmers) should well be able to deduce that these are  the inverse functional identifiers;
* Immediately above the other property table for Agent, which is practically the same, there is a line that says " The first four [properties]  are inverse functional identifiers."

Decided to add a similar line right above the Group object property table. Of course, a list of the four i.f.i can also be added if anyone thinks this is better. I'd prefer not to use the asterisk / stars since this isn't really a convention in the rest of the spec document.