Georgetown Law
Georgetown Law Library
Search all guides

Tax Research - Federal

This guide on federal tax research explains where and how to find tax materials.

Abbreviations & Acronyms

This chart assists with abbreviations and acronyms involved in tax law research.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

 

Abbreviation/Acronym Full Name  Definition More Information
Acq

Acquiescence 

When the IRS decides not to appeal a particular case, but announces it will fight similar issues as presented in the future. Announced by the IRS as an Action on Decision (AOD).

IRB Guidance

AFTR

American Federal Tax Reports

reporter of opinions for tax cases in federal district and appellate courts. Published by RIA.

Case Law

Ann

Announcements

Public pronouncements that have only immediate or short-term value (e.g., extension of filing deadlines for areas hit by natural disasters).

IRB Guidance

 

AOD

Action on Decision

When the IRS decides not to appeal a particular case, but announces it will fight similar issues as presented in the future. Announced by the IRS as an Action on Decision (AOD).

IRB Guidance

 

ARM

Appeals and Review Memorandum

Revenue Rulings issued before 1954 were called "Appeals and Review Memoranda."

IRB Guidance

ARR

Appeals and Review Recommendation

A type of Revenue Ruling issued before 1954.

IRB Guidance

BTA

Board of Tax Appeals

Case reporter for the Board of Tax Appeals, the precursor to the U.S. Tax Court.

Case Law

BTAM

Board of Tax Appeals Memorandum
Decisions

Case reporter for the Board of Tax Appeals, the precursor to the U.S. Tax Court.

Case Law

 

C.B.

Cumulative Bulletin

Official publication for IRS pronouncements (1919-2008).

IRB Guidance

CC

Chief Counsel Notice

Form of Chief Counsel Advice.

Other IRS Guidance

C.C.A.

Chief Counsel Advice

 

Other IRS Guidance

 

C.D.O.

Commissioner Delegation Order

Internal order delegating certain functions of the Commissioner for Internal Revenue to other officers/employees of the IRS.

IRB Guidance

IRS Website

CFR

Code of Federal Regulations

 

Regulations

Circ.

Treasury Circular

A form of agency rule by the Department of Treasury, which is published in the CFR.

Regulations

C.S.T.

Capital Stock Tax Ruling

Form of IRS ruling pre-1939 Code.

IRB Guidance

D.C.

Department Circular

General order by the Department of Treasury's Legal Division. 

Department of the Treasury

E.O.

Executive Order

 

Executive Orders

F.A.A.

Field Attorney Advice

Form of internal Chief Counsel Advice.

Other IRS Guidance

IRS Website

F.S.A.

Field Service Advice

Form of internal Chief Counsel Advice.

Other IRS Guidance

G.C.M.

General Counsel's Memoranda

Form of internal Chief Counsel Advice.

Other IRS Guidance

G.C.O.

General Counsel's Order

A type of Revenue Ruling issued before 1954.

IRB Guidance

INFO

Information Letter 

Statements of well-defined law; do not apply to particular facts. Issued to taxpayers and members of Congress.

IRS Website 

IRB

Internal Revenue Bulletin

The weekly publication of the Internal Revenue Service.

IRB Guidance

L.O.

Law Opinion

A type of Revenue Ruling issued before 1954.

IRB Guidance

L.R.
(also Ltr.Rul.,
P.L.R.,
Priv. Ltr. Rul.)

Letter Ruling

See Private Letter Ruling.

 

Mim.

Mimeograph

A type of Revenue Ruling issued before 1954.

IRB Guidance

M.S.

Miscellaneous Division Ruling

A type of Revenue Ruling issued before 1954.

IRB Guidance

Non-Acq (also NA)

Non-acquiescence

See AOD.

 
Notices    

IRB Guidance

O.D.

Office Decision

A type of Revenue Ruling issued before 1954.

IRB Guidance

Op. A.G.

Attorney General Opinion

A type of Revenue Ruling issued before 1954.

IRB Guidance

PLR
(also L.R.,
Ltr. Rul.,
Priv. Ltr. Rul.)

Private Letter Ruling

Written in response to a taxpayer's request for guidance as to the tax consequences of a proposed transaction.

Other IRS Guidance

 

Pro. Reg.
(Pro. Treas. Reg.)

Proposed Regulations

A proposed regulation, generally accompanied by a Notice of Proposed Rule Making (NPRM).

Regulation

Rev. Proc.

Revenue Procedures

Official statement of a procedure that affects the rights or duties of taxpayers under the Code, related statutes, regulations, and treaties that should be a matter of public knowledge. Generally provides instructions for return filing or other procedures. Sometimes may have a substantive effect (e.g., interest rate tables).

IRB Guidance

Rev. Rul.

Revenue Rulings

An official interpretation by the IRS of the Code, related statutes, regulation, and tax treaties. Explains the IRS's position on how the law is applied to a specific set of facts. 

IRB Guidance

RIA T.C. Memo.

Tax Court Memorandum Decisions

Tax Court memorandum decisions, unofficially published by RIA.

Case Law

S.C.A.

Service Center Advice

Form of Chief Counsel Advice concerning tax administration responsibilities.

Other IRS Guidance

 

S.M.

Solicitor's Memorandum

A type of Revenue Ruling issued before 1954.

IRB Guidance

Sol. Op.

Solicitor's Opinion

A type of Revenue Ruling issued before 1954.

IRB Guidance

S.R.

Solicitor's Recommendation

A type of Revenue Ruling issued before 1954.

IRB Guidance

Sp. Rul.

Special Ruling

A type of Revenue Ruling issued before 1954.

IRB Guidance

S.S.T.

Social Security Tax Ruling

A type of Revenue Ruling issued before 1954.

IRB Guidance

S.T.

Sales Tax Ruling

A type of Revenue Ruling issued before 1954.

IRB Guidance

TAM

Technical Advice Memorandum

Written guidance provided by the national office of the IRS upon the request of an IRS District Director or an IRS Area Director of Appeals. Responds to a technical or procedural question that develops during the examination of a taxpayer's return, the consideration of a taxpayer's claim for refund, or any other matter that involves the jurisdiction of a District Director or Area Director of Appeals.

Other IRS Guidance

T.B.M.

Advisory Tax Board Memorandum

A type of Revenue Ruling issued before 1954.

IRB Guidance

TC

Tax Court Regular Decision

A decision involving new or unusual points of law. Decided by the entire court en banc. Officially published in Tax Court Reports (T.C.).

Case Law

 

TCM

Tax Court Memorandum Decisions

A decision dealing with established legal issues and hinge on interpretations of fact. Decided by the trial judge. Unofficially published in two competing publications by CCH and RIA, both titled Tax Court Memorandum Decisions (T.C.M.). 

Case Law

TC Memo

Tax Court Memorandum Decisions

See TCM.

 

TC Summ Op.

Tax Court Summary Opinions

Issued in "small" cases, which is an expedited procedure for individual taxpayers with less than $10,000 in tax liability. Decisions are not appealable and are not considered precedent.

Case Law

TC ___ No.  

Temporary citation for a recent Tax Court decision.

Case Law

T.D.

Treasury Decision

An alternative numbering scheme for Treasury Regulations. This number is chronologically assigned.

Treasury Regulations

T.I.R.

Technical Information Release

Public guidance on technical developments.

IRB Guidance

T.M.
Tech. Mem.

Technical Memoranda

Form of Chief Counsel Advice.

Other IRS Guidance

 

Treas. Reg.

Treasury Regulation

Every Treasury Regulation is 26 C.F.R. [Treasury Regulation #].

Treasury Regulations

USTC

United States Tax Cases

A reporter of opinions for tax cases in federal district and appellate courts, published by CCH.

Case Law

Note: Many IRS rulings included in the chart are obsolete and no longer used. Obsolete documents are frequently cited, and some obsolete documents may still have legal standing.