Rejection
From Halopedia, the Halo wiki
Rejection is a Halo: Reach multiplayer medal. Depicted as a gold diamond superimposed by a blue shield and brass padlock, the medal is earned by using Armor Lock and surviving a subsequent assault that would have otherwise been fatal, i.e. a plasma mortar launched from a Wraith. It was revealed alongside two other medals in Bungie's 07/09/10 weekly update.[1]