From Unlocking the Files of the FBI: A Guide to Its Records and Classification System by Gerald K. Haines and David A. Langbart, Scholarly Resources Inc., 1993.
| Office Abbreviation/Code | Location |
| AL | Albany, NY |
| AQ | Albuquerque, NM |
| AX | Alexandria, VA |
| AN | Anchorage, AK |
| AT | Atlanta, GA |
| BA | Baltimore, MD |
| BH | Birmingham, AL |
| BS | Boston, MA |
| BQ | Brooklyn/Queens, NY |
| BU | Buffalo, NY |
| BT | Butte, MT |
| CE | Charlotte, NC |
| CG | Chicago, ILC |
| CI | Cincinnatti, OH |
| CV | Cleveland, OH |
| CO | Columbia, SC |
| DL | Dallas, TX |
| DN | Denver, CO |
| DE | Detroit, MI |
| EP | El Paso, TX |
| HN | Honolulu, HI |
| HO | Houston, TX |
| IP | Indianapolis, IN |
| JN | Jackson, MS |
| JK | Jacksonville, FL |
| KC | Kansas City, KS |
| KX | Knoxville, TN |
| LV | Las Vegas |
| LR | Little Rock, AR |
| LA | Los Angeles, CA |
| LS | Louisville, KY |
| ME | Memphis, TN |
| MM | Miami, FL |
| MI | Milwaukee, WI |
| MP | Minneapolios, MN |
| MO | Mobile, AL |
| NK | Newark, NJ |
| NH | New Haven, CT |
| NO | New Orleans, LA |
| NR | New Rochelle, NY |
| NY | New York City, NY |
| NF | Norfolk, VA |
| OC | Oklahoma City, OK |
| OM | Omaha, NE |
| PH | Philadelphia, PA |
| PX | Phoenix, AZ |
| PG | Pittsburgh, PA |
| PD | Portland, OR |
| RH | Richmond, VA |
| SC | Sacramento, CA |
| SL | Saint Louis, MO |
| SU | Salt Lake City, UT |
| SA | San Antonio, TX |
| SD | San Diego, C |
| SF | San Francisco, CA |
| SJ | San Juan, PR |
| SV | Savannah, GA |
| SE | Seattle, WA |
| SI | Springfield, MO |
| TP | Tampa, FL |
| WFO | Washington, DC field office |
| Office Abbreviation/Code | Location |
| BER | Bern, Switzerland |
| BOG | Bogota, Columbia |
| BON | Bonn, Germany |
| HON | Hong Kong, China |
| LON | London, England |
| MAN | Manila, Philippines |
| MEX | Mexico City, Mexico |
| OTT | Ottawa, Canada |
| PAN | Panama City, Panama |
| PAR | Paris, France |
| ROM | Rome, Italy |
| TOK | Tokyo, Japan |