23C: Assessment Date
ACC: Associate Chief Counsel
ACI: Appeals Coordinated Issues
ACR: Audit Change Report
ACS: Automated Collection Service
ACS: Automated Collection Services
ADEPT: Automated Deposit of Electronic Payments for Taxes
ADP: Automatic Data Processing
ADR: Alternative Dispute Resolution Procedures
AGI: Adjusted Gross Income
AICPA: American Institute of Certified Public Accountants
AIMS: Audit Information Management System
AM: Area Manager
AO: Appeals Officer
AOC: Advice of Credit
AOD: Actions on Decisions
ASED: Assessment Statute Expiration Date
ATAO: Application for Taxpayer Assistance Order to Relieve Hardship
ATG: Audit Technique Guide
ATIN: Adoption Taxpayer Identification Number
AUR: Automated Under Reporter
AWISS: Agency Wide Information Systems Services
AWSS: Agency Wide Shared Services
BeST: Benefits and Services Team
BMF: Business Master File
BWH: Backup Withholding
C&L: Communications & Liaison
CAF: Centralized Authorization File
CAP: Collection Appeals Process
CARE: Communications, Assistance, Research & Education
CAS: Computer Audit Specialist
CAS: Customer Account Services
CAS: Customer Accounts Service
CBAF: Commercial Bank Address File
CC: Chief Counsel
CC: Command Code
CCO: Computing Center Operations
CCR: Comprehensive Case Resolutions
CDP: Collection Due Process
CEP: Coordinated Examination Program