List of Halo 4 commendations/Player

Dawn
Complete the campaign mission Dawn on Legendary difficulty

Requiem
Complete the campaign mission Requiem on Legendary difficulty

Forerunner
Complete the campaign mission Forerunner on Legendary difficulty

Infinity
Complete the campaign mission Infinity on Legendary difficulty

Reclaimer
Complete the campaign mission Reclaimer on Legendary difficulty

Shutdown
Complete the campaign mission Shutdown on Legendary difficulty

Composer
Complete the campaign mission Composer on Legendary difficulty

Midnight
Complete the campaign mission Midnight on Legendary difficulty

Legend
Complete all of the following commendations: Dawn, Requiem, Forerunner, Infinity, Reclaimer, Shutdown, Composer, Midnight. Completing this commendation will unlock the Mark VI armor set, the "Legendary" visor, and the "117" emblem

Spartan Slayer
Take out enemy Spartans. Completing this commendation will unlock the CIO armor set, and the "Extracted" emblem

Bullet in the Brain
Take out enemy Spartans with headshots. Completing this commendation will unlock the Defender "Control" (CTRL) armor set

First Strike
Get the first kill in a match. Completing this commendation will unlock the "Assault" stance

Multikill
Earn any of these 8 medals: Double Kill, Triple Kill, Overkill, Killtacular, Killtrocity, Killamanjaro, Killtastrophe, Killpocalypse. Completing this commendation will unlock the Infiltrator "Trace" (TRAC) armor set

Assassin
Assassinate enemy Spartans. Compleing this commendation will unlock the Venator armor set

Spartan Spree
Earn any of these 7 medals: Killing Spree, Killing Frenzy, Running Riot, Rampage, Untouchable, Invincible, Inconceivable. Completing this commendation will unlock the Soldier "Zenith" (ZNTH) armor set

Assistant
Earn any of these 4 medals: Assist, Vehicle Destroy Assist, Distraction, EMP Assist. Completing this commendation will unlock the "Sunspot" visor

Protector
Earn any of these 3 medals: Protector, Guardian Angel, Savior. Completing this commendation will unlock the Ranger "Strike" (STRK) armor set

Close Quarters
Earn any of these 3 medals: Melee, Beat Down, Bulltrue. Completing this commendation will unlock the Twin-plated "Aeon" (AEON) forearms

Combat Opportunity
Earn any of these 5 medals: Killjoy, Headcase, From the Grave, Reload This, Showstopper. Completing this commendation will unlock the Ranger armor set

Payback
Kill the enemy Spartan that just killed you. Completing this commendation will unlock the Contoured "Shard" (SHRD) legs

Avenger
Kill an enemy Spartan that just killed a teammate. Completing this commendation will unlock the "Blindside" visor

From the Brink
Kill an enemy Spartan while close to death. Completing this commendation will unlock the "Cyan" visor

Hail of Death
Call in personal ordnance. Completing this commendation will unlock the EVA "Breach" (BRCH) armor set, and the "Ordnance" emblem

Perfection
Complete a match without dying and get at least 15 kills. Completing this commendation will unlock the Contoured "Shard" (SHRD) forearms

Exterminator
Killed every enemy Spartan that finished the match. Completing this commendation will unlock the Recruit "Tiger" (TIGR) legs