I am creating this thread strictly on informative purposes. As we know, CEA ties into Reach with its multiplayer. For those who may not know, while playing through CEA's campaign you can find terminals hidden in the missions. Each one of those hidden terminals contains a forerunner code at the very end of the transmission.
When you open Halo Waypoint on your system and pres the X button, you will have to enter the button combination to unlock a forerunner keypad. Use this keypad to enter the symbols that are found in each terminal to unlock credits for use in Reach. Each terminal is worth 7,000 cr with the exception of "The Maw" which is worth 37,000 cr. All together you recieve 100,000 cr plus a bonus 11th terminal called Threshold.
Now, with that being said, that leads me to my next theory. The GRD dolls that are hidden throughout the new maps are clues. I believe there are forerunner symbols hidden somewhere on that map that you can enter on waypoint to unlock this helmet. The terminals only require 5 symbols, but you can enter up to 10. Seems strange to me. I will begin hunting symbols sometime today. If anyone has any clues they come across, please post them here so everyone can be helped. Thanks all.
[Edited on 11.19.2011 6:26 AM PST]