Might raise a wishlist bug to move to using enums to give the numbers meaning as it's not immediately clear what they are defined for.

What I can deduce:
1 - Is a COM class or interface
2 - Class has no pointers
4 - ??? (bit is always set)
8 - Class has default constructor
16 - Not an interface??? (only set for classes)
32 - ??? (bit is always set)
64 - Class is abstract

So I guess you have two free flags to choose from.