"Chief counsel advice is an umbrella term that encompasses any written advice prepared by any National Office component of the Office of Chief Counsel or division counsel headquartered in Washington and issued to IRS counsel or field office employees that conveys a legal interpretation or IRS counsel position or policy regarding a revenue provision." (IRS Guidance 1980-2003: An Ever-Changing Landscape, Tax Notes)
"Chief Counsel Advice (CCA) materials are written advice or instructions prepared by the Office of Chief Counsel and issued to field or service center employees of the IRS or Office of Chief Counsel." (IRS Website)
"IRC § 6110(i)(1)(A) defines CCA as written advice or instruction, under whatever name or designation, prepared by any National Office component of the Office of Chief Counsel that A. Is issued to Field or Service Center employees of the Service or Field employees of the Office of Chief Counsel, and B. Conveys any legal interpretation of a revenue provision, any Service or Office of Chief Counsel position or policy concerning a revenue provision, or any legal interpretation of State law, foreign law, or other Federal law relating to the assessment or collection of any liability under a revenue provision. CCA includes both taxpayer specific and nontaxpayer specific advice." (Definition of Chief Counsel Advice, IRM § 33.1.3.1.1)
Below is a pertinent abbreviation.
Below are links to select sources offering chief counsel advice. Consult other pages in this guide for other types of advice from IRS attorneys.