Did you know TF2

[Desert]

Before the first update that added hats Valve put joke text in the game which confused many players who wanted early info on the hats. The text made it appear as if Valve was making TF2 into an MMO

// TF2 MMO
"TF_MMO_LFG" "Looking For Group"
"TF_MMO_Quest1" "You must kill %s1 %s2 to complete this quest."
"TF_MMO_Monster1" "Boars"
"TF_MMO_Monster2" "Rats"
"TF_MMO_Monster3" "Bats"
"TF_MMO_Monster4" "Wolves"
"TF_MMO_Monster5" "Spiders"


There's also name strings that reference unused weapons.

"TF_Weapon_Nailgun" "Nail Gun"
"TF_Weapon_Tranq" "Tranquilizer Gun"
"TF_Unique_Achievement_SniperRifle" "Walkabout" // ADD THE
"TF_Unique_Logo_Shield" "Heraldic Targe" // ADD THE
"TF_Weapon_Crowbar" "Crowbar"
"TF_Weapon_SuperSMG" "Super SMG"
"TF_Weapon_Flag" "Flag"


Source: http://tcrf.net/Team_Fortress_2/Unused_Text