http://www.irs.gov/publications/p503/ IRS Publication 503 publication 503 IRS Publication 503 IRS Publication 503 IRS Publication 503 http://www.irs.gov/publications/p503/ http://www.irs.gov/publications/p503/ http://www.irs.gov/publications/p503/ http://www.irs.gov/publications/p503/ IRS web site http://www.irs.gov/publications/p503/ http://www.irs.gov/publications/p503/