Kathleen Pakenham, Danielle M. Smith & Tricia Marlar (all of White & Case, New York) have published IRS Releases Tax Shelter Audit Technique Guide, 108 Tax Notes 337 (July 18, 2005), also available on the Tax Analysts web site as Doc 2005-14209, 2005 TNT 138-32.  Here is the abstract:

In May 2005, the IRS released an audit technique guide (ATG) developed to help field personnel identify abusive tax shelters and transactions that it has been using internally for some time. The guide’s goal is to cover all types of transactions and serve as a reference for IRS agents. Based on previous IRS papers, documents, and guides, the authors believe the ATG provides a useful and comprehensive overview of tax shelters, their history, and efforts to combat them. The guide also analyzes the characteristics of listed transactions (transactions that the IRS has determined to be abusive tax shelters) and abusive arrangements that are not listed. The guide discusses relevant judicial doctrines and describes resources that are available to field personnel and investigatory tools that are at their disposal. The guide also sets out what factors should guide IRS agents in developing tax shelter abuse cases and provides a brief overview of various appeals procedures taxpayers may use to resolve disputes.