Perhaps you were looking for one of these?

• AACX State of Alaska, Division of Agriculture
• AB Akron and Barberton Cluster Railway Company
• ABB Akron and Barberton Belt Railroad Company
• ABFZ Arkansas Best Freight
• ACIX Great Lakes Chemical Corporation
• ACPX Union Tank Car Company
• ACY Akron, Canton & Youngstown
• ACZX Norfolk Southern Railway Company
• ADIX Adirondack Railway Preservation Society
• AEIX Alan Eslisk
• AFIZ Agmark Foods
• AGILIS agilis Verkehrsgesellschaft
• AGLF Knoxville & Holston River Railroad
• AGMU Agmark Foods Inc
• AIKR AIKR
• AK AK
• AKIEM AKIEM - France
• AKLU K Line
• AKM American Kraft Mills
• AKMD Arkansas Midland Railroad Company
• AKN AKN
• AKS AK Steel
• AKZX AKZO Nobel Chemicals Incorporated
• ALKX Airlake Terminal Railway Co.
• ALM Arkansas Louisiana and Mississippi Railr
• ALT AIRLAKE TERMINAL RAILWAY COMPANY
• ALTU VTG Vereinigte Tanklage U Transportmittel GMBH
• AM Arkansas & Missouri
• AMBX American Boiler Works Incorporated
• AMC Arkansas Louisiana and Mississippi Railr
• AMK AMK
• AMKT AMKT
• AMLU Alaska Marine Lines
• AMMX Kentucky-Tennessee Clay Company
• AMOX Union Tank Car Company
• AMTAK AMTAK
• AMTK Amtrak
• AMTZ Amtrak (National Railroad Passenger Corporation)
• ANDX Andesite Rock Company
• ANKX A and K Railroad Materials Incorporated
• AOK Arkansas-Oklahoma Railroad
• AOKF AOKF
• APEX Apex Tank Car Line
• APMU Maersk Lines
• APMZ Maersk Equipment Service Co.
• AR Aberdeen and Rockfish
• ARR Alaska Railroad
• ARSX BRASKEM AMERICA INC
• ASV Abilene & Smokey Valley
• ATSF Atchison Topeka & Santa Fe