Civilian

From WoWWiki

This concept was removed from the game in patch 2.0.

From Patch 2.0 Honor System Changes at the official site:

How will dishonorable kills factor in to the new honor system?

Although this is subject to change, we are not currently planning to have dishonorable kills play any role in the honor system. The NPCs around the world will no longer be set as civilians, so killing them will not impact your ability to obtain honor points.

The subject of this article has been removed from World of Warcraft. This includes items and quests that can no longer be obtained. The in-game information in this article is kept purely for historical purposes and should probably not be under any other categories.

A type of NPC that will garner a Dishonorable Kill if killed during PvP combat. The Civilian status should appear in their description when the pointer is moved over them.

Many complaints have been raised since their existence due to the fact it almost completely destroyed town/city raiding, due to the fact one Dishonorable Kill could destroy weeks of work for a high ranked player. However it has been announced that in patch 1.12 World PvP objectives will be released.

They were added to the game by Blizzard in an effort to stop high level players camping quest NPCs or vendors without penalty, as this could become a major source of grief for lower level players on older servers.

Also known as Civies and Civs, or just called a "DK".