Back when they first implemented the honour system (march 2005-ish), Blizzard held a contest.  On every server, players from each faction were set the challenge to get the most honour kills in a set time limit.  The winner would receive this unique tabard.
Only one alliance player and one horde player per server received the item.
The Tabard was given out to the member of each faction of each realm with the most honorable kills BEFORE introduction of the honor system. A friend of mine was one of them.
CRAP..u could get it in 2004(or 2005 i dont no) and you will get it by a GM. There was a Saison where u must be the best one of killing, the Player who kills the most other players ( alliance or horde ). One get it by alliance and one get it by the horde! Sorry 4 my bad english ) i hope u unterstand all.
Here's a pic of me wearing the tabard, I found it in a tabard file, the code for it is 19160, if anyone knows how to use GM commands... http://www.teamsx3.com/1256.gif
it is not true you have to be first rank 14 on your server to get this, somebody in my guild got it and i think he was only ever rank 13. Think it is something to do with getting an insane amount of honour though.
In fact - if i remember right - it was given 1 month after the honor system started. The ones with the highest HKs of each faction got it/server. Coolest tabard ever, good old SS-Tm fights.
My friend received this tabard at random on a sub level 20 alt. Anyone have any idea why that might be? As far as I know he didn't enter any comps and he certainly isnt HWL or GM.