little aside, those people that work for the charities can get just under $20K of their wages diverted into a special credit card (that can be used anywhere a normal credit card can be used).
That money is not declared to the tax office as income, so it is $20K odd of income that is tax free. (so basically they do not start paying any income tax until they get to near $40K of income).
Does not matter what job you do, you just have to work for a charity type place.