The Covenant Halo 2 Poster Cipher is an alphabet currently only used once on posters released on the 30th November 2004.
How it was crackedEdit
First Bungie released two posters.
Fans quickly realised that the triangle symbols translated into terms used by Bungie for the Master Chief (Flawless Cowboy) and Brutes (Jiralhanae), and if any letters/symbols were shared between the wallpapers they were the same letter. Giving us A, B, C, E, F, H, I, J, L, N, O, R, S, W, and Y.
Further notesEdit
As this cipher has never seen use since these two wallpapers, it is unlikely this will ever see use again, so the cipher wont be completed.