An abusive scheme toolkit for external stakeholders Table of contents Introduction Facts Law and arguments - The voluntary nature of the federal income tax system The meaning of income: taxable income and gross income The meaning of certain terms used in the Internal Revenue Code Constitutional amendment claims Fictional legal bases The truth about frivolous tax arguments Talking points Publication 3995, Recognizing Illegal Tax Avoidance Schemes PDF Questions and answers Referrals/contacts Form 14242, Report Suspected Abusive Tax Promotions or Preparers PDF