IRS Form 5471 w/ respect to Foreign Corporations

Form 5471 requires you state your "Category" as a Filer. I am wondering if anyone out there works with U S Persons and Foreign Corporations, and if yes do you know the difference between a Category 2 Filer and a Category 3 Filer w/ respect to the Form 5471?

I believe the Category 2 Filer is a U S citizen or resident who is an officer or director of a foreign corporation in which a U S Person has at least 10% stock but who does not necessarily own any stock him/herself, and

the Category 3 Filer is the U S Person - not necessarily and officer - who actually owns the stock.

My client is a U S Person who owns 50% stock in a foreign corporation (Category 3) and is ALSO the director of the corporation in which a U S Person (himself) owns =>10% stock in a foreign corporation (Category 2)

Can he be both? Must he declare both, and as such file all schedules on the 5471 as both a Category 2 and a Category 3 filer?