Possible "enhancement"?

OK, I hope ya'll don't mind a thought from a newbie. And I hope this is
the right forum to ask about this. I was wondering if it would be possible
(no I don't have the expertise!) to extend one of the system tables. What
I was hoping for was somewhere to store the "options" used to create
columns. In particular, I create a column similiar to:

name text not null references other_table(name) on delete cascade
on update cascade deferrable initially deferred

Well this works wonderfully. However, unless I'm really good about
documentation (I'm not really), then I may forget about one of those
attributes. I know that they are implicitly there if I carefully look at
the TRIGGERs created. But I think that it might be nice to have a column
in one of the system tables (whichever one describes the rows) which would
contain this information.

I hope that I'm making some sense to you.

Thank you for a very nice ORDBMS! I do appreciate you're efforts.

John