HUD or, Heads Up Display. The HUD is what shows your Health, and Armour. It is what shows you what weapon you are using as well as how much ammo you have. It is what provides your essential information. class skills, map information (such as cap points held on cz2), Death messages, messages sent when players touch a dispenser or have their dispenser touched. Text messages, voice channels and so forth. Break everything down into subtopics if any detail is involved, using the prefix HUD:.
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Health and Armour
Whenever you walk over a backpack, the ammo you've obtained will appear on the right side of the screen.
Engineer MessagesWhen you build something as a Engineer, a persistant message will appear on the right side of your screen, showing you the status of your built objects.
Map Objective Information
Filling out later.
When someone is killed in the game, a message will appear on the upper-right corner showing who killed that person. The name on the left is the attacker, the icon is the weapon that was used for the kill and the name on the right is the victim.