[LANG] Sign script, message display.

[Hauken]

So I wish to use signs that frictional used at the Archives level near start of the game.

I know that i must use the entity itself which is the sign, and then I need to add the area same size as the sign.
I must set the Area trigger as Sign and give it a name.

However I do not know the commands I need to add to my LANG file, I tried to find frictional games LANG file for this level but I cant find them, neither do I know if I can find them..

Has anyone done this before ?
I also cant find my way to the big functions list on the wiki