These callsigns are entered by the flight or ground crews.
I started in 1998 with a basic list that I pulled off of the web.
Joseph, MO BRADY HC-130P USAF AFRC/920RQW/39RQS Patrick AFB FL BRADY C-130H-30 336sqn Netherlands Air Force BRADY KC-130J VMGR-352 MCAS Cherry Point NC BRADY C-130J-30 RI ANG 143AW/143AS Quonset Point RI BRAG F-16CJ, 55 FS/20 FW Shaw AFB SC BRANDY F-16s, Luke AFB AZ BRANDYWINE SATCOM/GEP center Joint Base Andrews MD BRASS HAT NORAD General Co Springs BRAT F-16 115th FW, Madison, WI BRAT F15E 494th FS, RAF Lakenheath BRAVE F-16 135th FW OK ANG Tulsa ANGB OK BRAVE 22nd ARW, Mc Connell AFB, KS BRAVE F-16 121ST FS DC ANG Joint Base Andrews MD (Scramble/Travelling) BRAVE F-16 138th FW, OK-ANG, Tulsa, OK BRAWLER OPS 4-3 AVN, AHB Hunter AAF Savannah GA BRAY RC-135 55th Wing, Offutt AFB, NE BREM BOEING FLIGHT TEST, ST. LOUIS MO BUDDHA F-16C/D 100th FS AL ANG Dannelly Fld Birmingham AL BUDDHA F-22, 27th/94th FS Joint Base Langley-Eustis VA BUDMAN F-16 113TH FW 121ST FS DC ANG Joint Base Andrews MD BUDDY KC-135R 22nd ARW Mconnell AFB KS BUFF B-52 2nd Wing, Barksdale AFB, LA BUFFOON C-130H 164th AS, OH ANG Mansfield OH BUGGY RIDE DEPARTURE FROM BASE DUE TO CIVIL DISTURBANCE/DISASTER BUGSY F-22, 27th/94th FS Joint Base Langley-Eustis VA BUILD C-130H 440th AW, Milwaukee, WI BULB C-130H 910th AG, Youngstown, OH BULL C-130H 103rd AW/118th AS, CT ANG Bradley ANGB CT BULL C-130 314th OG, Little Rock AFB, AR BULL F/A-18 VFA-37, NAS OCEANA VA BULL F-22, 27th/94th FS Joint Base Langley-Eustis VA BULL F-15 123rd FS OR ANG Portland IAP OR BULLDOG A-10 354TH FS DAVIS-MONTHAN AZ BULLDOG F-16 124th FS IA ANG Des Moins IA BULLDOG MAJOR Alabama Ar NG BULLET F-18F VF-2, Bounty Hunters" CVW-2 NAS Lemoore CA BULLET MH-53 16th SOS, Hurlburt Fld FL BULLET F-16 457th FS TX ANG JRB Fort Worth TX BULLET A-10 Selfridge ANGB, MI BULLIT F-16CJ, 55 FS/20 FW Shaw AFB SC BULLFROG TANGO Seal Beach Naval Weapons Station, CA BULLSEYE CC-130H CANFORCE 17TH WING CFB WINNEPEG BULLSEYE SOF Nellis AFB NV BULLY F-16C/D 121ST FS Joint Base Andrews MD BUMPY E-6A Navy E-6 Mercury BUNCH B-2, 509th Bomb Wing; Whiteman AFB MO BUNK MC-130 16th OG, HURLBURT FIELD FL BURGER F-15 SEYMOUR JOHNSON AFB, NC AFB SC BURGLAR MC-130H 550th SOS, Kirtland AFB, NM CP BURMA CC-130J CANFORCE 8TH WING CFB TRENTON BURNER F-15C/E 85th TES Eglin AFB FL BURNER F-15C/D 33rd FW Eglin FL BURNER T-38 49th FW, Holloman AFB, NM BURNER F-22 327th FW/43rd FS Tyndall AFB FL BURNING BUSH NAS Whidbey Island, WA CP BURR C-130 16th SOW, Hurlburt Field AFB, FL BURSA C-20/C-21 76th AS, Ramstein AB GE BURT EC-135 552nd ACW, Tinker AFB, OK BUSCH F-15 131ST FW/ 110TH FS MO ANG LAMBERT INTNL. LOUIS MO BUSH A-10 303rd Sqdn, 442nd FW; Whiteman AFB MO BUSHMASTER CP KIOWA MOA RANGE CONTROL PA BUSHMASTER CP Townsend MOA RANGE CONTROL GA BUST E-4B USAF/ACC 55 Wing/1ACCS OF Offut NE BUSTER A-10 MOODY AFB GA BUSTER A-10 303rd Sqdn, 442nd FW; Whiteman AFB MO BUST OUT NO NOTICE LAUNCH OF STRATCOM POSITIVE CONTROL FORCE BUTCH E-3B 552nd ACW, Tinker AFB, OK BUTCH C-32B #02-4452/227th SOF, NJ-ANG, Mc Guire AFB, NJ BUTCH KC-135R/T 319th ARW Grand Forks AFB ND BUTLER F-15E, 4 FW SEYMOUR JOHNSON AFB, NC BUZZ C-130 352nd SOG, RAF Mildenhall, UK BUZZ T-45C, VT-7 Meridian MS BUZZ F-15D, OR-ANG BUZZARD P-3C, NAS Jacksonville FL ME.
LOUIS MO BREVET T-39 VT-86, NAS Pensacola FL BREW B-52 2nd Wing, Barksdale AFB, LA BREW F-16 134th FS VT ANG Burlington VT BREW F-15 123rd FS OR ANG Portland IAP OR BREW F-15E USAFE 48FW / 492FS LN Lakenheath BREW T-1A Jayhawk 71st FTW; Vance AFB; Enid, OK BREWER C-130H 440th AW, Pope AFB NC BREWER C-130H, 95AS/440AW Moody AFB GA BRICE KC-135R 126th ARW, IL ANG Scxott AFB IL BRICK F-16 187TH FG AL ANG MONTGOMERY AL BRICK C-21A Air Force Flight Standards Agency (AFFSA) Tinker AFB OK BRICKSTON CH-53 HM-12, NAS Chambers, VA BRICKWALL AMC ALCC, Osan AB Korea BRICKYARD KC-135R 434th ARW, Grissom ARB, IN BRICKYARD 87th AMW Command Post, Joint Base-Mc Guire-Dix-Lakehurst NJ BRICKYARD P-3C/P-8 Poseidon, deployed to Middle East/Persian Gulf. BUZZARD TA-4J VT-22, Kingsville, TX BUZZARD F-16C/D 510th FS Aviano Italy BUZZSAW US Customs JTF-4 BUZZY F-22, 27th/94th FSJoint Base Langley-Eustis VA BYLAW E-3B 552nd ACW, Tinker AFB, OK CABAL KC10 60th AMW, Travis AFB CA CABIN CRUISER US Customs AB, Caribbean CACTI VAR FERRY TANKERS CACTUS 133rd AW MN ANG Minneapolis-St.
Reach callsigns suffixes are usually either a mission number or some variation on the aircraft tail number.
Fighters: The following is from a knowledgable source: As far the numbering convention is concerned, the 11, 21, etc. Therefore, we normally assign the numbers of those formations as a sequence, i.e. Where there are multiple flying squadrons at a base, they assign each squadron a series of 3 numbers, 0-8.