A new code has been discovered my the hard-working boffins over on the Waypoint Forums. This one gets you 12116XP for Halo 4, the "Recruit" emblem (which came with the LE game) as well as a link to this image:
With the question "Where were you that day?"
This brings us up to a total of 6 codes! Which you can enter here.
1 - 500XP and SPEC/Raider Shoulder Armour [Prerequisite: Complete Spartan Ops Mission 1]
2 - 500XP and Spec/Raider Torso Armour [Prerequisite: Complete Spartan Ops Mission 2]
3 - 5000XP a Concept Art Gallery and ONI Emblem [Prerequisite: Complete Spartan Ops Mission 3]
4 - 2000XP a Concept Art Gallery and Wiseguy Emblem [Prerequisite: Find the Seven campaign Terminals]
5 - 500 XP and SPEC/Raider Helmet [Prerequisite: Enlist in Infinity Multiplayer]
6 - 12116XP and the Recruit emblem
- Cowboy Out.