WoWInterface - Short Chat Channelnames

i dont remember who i pulled this off, works in retail and beta.
Code:
local rplc = {"[GEN]","[T]","[WD]","[LD]","[LFG]","[GR]","[i]","[IL]","[G]","[P]","[PL]","[PL]","[O]","[R]","[RL]","[RW]","[%1]"}



local gsub = gsub

local time = _G.time

local newAddMsg = {}

local chn = {

        "%[%d%d?%. General[^%]]*%]",

        "%[%d%d?%. Trade[^%]]*%]",

        "%[%d%d?%. WorldDefense[^%]]*%]",

        "%[%d%d?%. LocalDefense[^%]]*%]",

        "%[%d%d?%. LookingForGroup[^%]]*%]",

        "%[%d%d?%. GuildRecruitment[^%]]*%]",

        gsub(CHAT_INSTANCE_CHAT_GET, ".*%[(.*)%].*", "%%[%1%%]"),

        gsub(CHAT_INSTANCE_CHAT_LEADER_GET, ".*%[(.*)%].*", "%%[%1%%]"),

        gsub(CHAT_GUILD_GET, ".*%[(.*)%].*", "%%[%1%%]"),

        gsub(CHAT_PARTY_GET, ".*%[(.*)%].*", "%%[%1%%]"),

        gsub(CHAT_PARTY_LEADER_GET, ".*%[(.*)%].*", "%%[%1%%]"),

        gsub(CHAT_PARTY_GUIDE_GET, ".*%[(.*)%].*", "%%[%1%%]"),

        gsub(CHAT_OFFICER_GET, ".*%[(.*)%].*", "%%[%1%%]"),

        gsub(CHAT_RAID_GET, ".*%[(.*)%].*", "%%[%1%%]"),

        gsub(CHAT_RAID_LEADER_GET, ".*%[(.*)%].*", "%%[%1%%]"),

        gsub(CHAT_RAID_WARNING_GET, ".*%[(.*)%].*", "%%[%1%%]"),

        "%[(%d%d?)%. ([^%]]+)%]"

}

local AddMessage = function(frame, text, ...)

        for i = 1, 17 do

                text = gsub(text, chn[i], rplc[i])

        end

        text = gsub(text, "%[(%d0?)%. .-%]", "[%1]")

        return newAddMsg[frame:GetName()](frame, text, ...)

end



for i = 1, NUM_CHAT_WINDOWS do

        local f = "ChatFrame"..i

        if i ~= 2 then -- skip combatlog

                newAddMsg[f] = _G[f].AddMessage

                _G[f].AddMessage = AddMessage    

        end

end