The Phonetic Alphabet is the primary naming system used for small vessels. The United Nations Space Command uses the NATO phonetic alphabet.

Letter	Code word	Pronunciation	IPA from ICAO
A	Alfa (ICAO, ITU, IMO, FAA) Alpha (ANSI)	AL FAH	pronounced ˈælfɑ
B	Bravo	BRAH VOE	pronounced ˈbrɑːˈvo (sic)
C	Charlie	CHAR LEE  or SHAR LEE	pronounced ˈtʃɑːli (sic)  or pronounced ˈʃɑːli (sic)
D	Delta	DELL TAH	pronounced ˈdeltɑ
E	Echo	ECK OH	pronounced ˈeko
F	Foxtrot	FOKS TROT	pronounced ˈfɔkstrɔt
G	Golf Gamma	GOLF/GA MAH	pronounced gʌlf (sic) pronounced ˈɡæmə
H	Hotel	HO TELL (ICAO) HOH TELL (ITU, IMO, FAA)	pronounced hoːˈtel
I	India	IN DEE AH	pronounced ˈindiˑɑ
J	Juliett (ICAO, ITU, IMO, FAA) Juliet (ANSI)	JEW LEE ETT	pronounced ˈdʒuːliˑˈet
K	Kilo	KEY LOH	pronounced ˈkiːlo
L	Lima	LEE MAH	pronounced ˈliːmɑ
M	Mike	MIKE	pronounced mɑik
N	November	NO VEM BER	pronounced noˈvembə (sic)
O	Oscar	OSS CAH	pronounced ˈɔskɑ
P	Papa	PAH PAH	pronounced pəˈpɑ
Q	Quebec	KEH BECK	pronounced keˈbek
R	Romeo	ROW ME OH	pronounced ˈroːmiˑo
S	Sierra	SEE AIR RAH (ICAO, ITU, IMO) SEE AIR AH (FAA)	pronounced siˈerɑ
T	Tango	TANG GO	pronounced ˈtængo (sic)
U	Uniform	YOU NEE FORM  or OO NEE FORM	pronounced ˈjuːnifɔːm (sic)  or pronounced ˈuːnifɔrm
V	Victor	VIK TAH	pronounced ˈviktɑ
W	Whiskey	WISS KEY	pronounced ˈwiski
X	X-ray or Xray	ECKS RAY (ICAO, ITU) ECKS RAY (IMO, FAA)	pronounced ˈeksˈrei
Y	Yankee	YANG KEY	pronounced ˈjænki (sic)
Z	Zulu	ZOO LOO	pronounced ˈzuːluː
0	Zero (FAA) Nadazero (ITU, IMO)	ZE RO (ICAO, FAA) NAH-DAH-ZAY-ROH (ITU, IMO)	—
1	One (FAA) Unaone (ITU, IMO)	WUN (ICAO, FAA) OO-NAH-WUN (ITU, IMO)	—
2	Two (FAA) Bissotwo (ITU, IMO)	TOO (ICAO, FAA) BEES-SOH-TOO (ITU, IMO)	—
3	Three (FAA) Terrathree (ITU, IMO)	TREE (ICAO, FAA) TAY-RAH-TREE (ITU, IMO)	—
4	Four (FAA) Kartefour (ITU, IMO)	FOW ER (ICAO, FAA) KAR-TAY-FOWER (ITU, IMO)	—
5	Five (FAA) Pantafive (ITU, IMO)	FIFE (ICAO, FAA) PAN-TAH-FIVE (ITU, IMO)	—
6	Six (FAA) Soxisix (ITU, IMO)	SIX (ICAO, FAA) SOK-SEE-SIX (ITU, IMO)	—
7	Seven (FAA) Setteseven (ITU, IMO)	SEV EN (ICAO, FAA) SAY-TAY-SEVEN (ITU, IMO)	—
8	Eight (FAA) Oktoeight (ITU, IMO)	AIT (ICAO, FAA) OK-TOH-AIT (ITU, IMO)	—
9	Nine (FAA) Novenine (ITU, IMO) No 'r' in spellings	NIN ER (ICAO, FAA) NO-VAY-NINER (ITU, IMO)	—

Uses in Halo

• Pelican dropships are identified by a serial number consisting of one letter from the Phonetic Alphabet and three numbers. Examples: Echo 419, Victor 933, Bravo 022, Kilo 023.
• Fireteams are distinguished by Phonetic letters. Example: Fireteam Zulu.
• Bumblebee lifepods have serial numbers using three letters from the Phonetic alphabet.
• Marines use them in place of abbreviations in the field for weapons, vehicles, units, and sometimes common sayings.
  • Covenant forces are called "Echo Tango" (E.T.) in battle, which is often shortened to just "Tango".
  • A nickname for Brutes is "Baby Kong." Marines often say "Bravo-Kilo" instead, usually in interviews or testimonials.
  • Dutch uses "Oscar-Mike", meaning "On the move." Also he is often heard using "Mike-Foxtrot" as self-imposed censorship for "mother fucker."
• SPARTANs are often referred to as "Sierras" by themselves and other UNSC personnel.
• Dr. Catherine Halsey uses the Phonetic alphabet to construct an alias matching her initials, "Charlie Hotel", in the epilogue of Halo: Contact Harvest.