I just tried this on Halo Waypoint and it is pretty cool.
At the end of every terminal you find in CEA, there will be 5 symbols, if you write these down (in order) and press X at the main menu for Waypoint, you will see a combination of multi-colored circles, press the buttons on you controller matching these colors, and you will be brought to a page with several symbols you have seen in the terminals. Enter the symbols in the order you saw them in the terminal and you will get 7000 Credits!! (37000 for the terminal in "The Maw") The terminals must have been found and activated in your game for these codes to work, so you can't just use youtube, although it helps with remebering the codes, as they do not vary in different copies of CEA. This is a nice boost of 100,000 credits total in Halo Reach, so go out there and find some terminals.
-Snake :sorcerer: