A letter from the IRS, included in its application for last year's walkathon, indicates that Afrikan Heritage Walkathon is indeed exempt from federal taxes, and dates that exemption from February of 2005. The Form 990 is required, the letter dated Oct. 21, 2012 says, but a check of the IRS website finds just two "postcard" tax returns, called 990-Ns, from 2010 and 2012. ¿The 990-N is a one-page form with little detail. On it, the charity attests only that it collected less than $50,000 in total donations. Like all tax forms, they are due annually.