Hellomyname Keyes
From Halopedia, the Halo wiki
Hellomyname Keyes is an Easter Egg in Halo:Combat Evolved referring to an error on the nametag of Captain Keyes' uniform. A patch on Keyes' chest reads "HELLO MY NAME", and the patch beneath it reads "KEYES". It is speculated that, during the production process of the game, Bungie had no room to fit the missing word, is, on the tag. On the left of the badge is seen the Marathon symbol.
One can view the nametag using a 2x-zoomed pistol in the level the Pillar of Autumn or a 2x/8x/10x-zoomed S2 AM sniper rifle in the Truth and Reconciliation. The patch can be seen more reliably using Halo Map Tools; it is the first decal listed in Bitmap (capn_patches_decal). It can also be seen clearly in the cutscene during which the Master Chief arrives on the bridge of the Pillar of Autumn.