Every imbued Supernaturalis has access to number of powers (see ‘help powers’). The maximum number of ranks you may have divided among your powers is equal to your Age squared, divided by 1000, with your three highest ranked powers not counting towards the total. The maximum rank you may have in any one power is equal to 10% of your Age.
This means that a newly classed character at Age 100 can have 3 powers at rank 10, and an additional 10 ranks distributed as desired. An Age 200 character can have 3 powers at rank 20, and an additional 40 distributed ranks. An Age 300 character can have 3 powers at rank 30, and an additional 90 distributed ranks. And so on.
Your ‘potential’ (as listed in your score, assuming you’re classed) represents what percentage of your maximum ranks you’ve trained. Thus 100% potential for an Age 100 character means they have 3 powers at rank 10, and an additional 10 ranks divided among their other powers.