.Map :: MoHAA Mapping

I know to use calk for bridge, buildings, ect.... But do I use calk sky for the outside of my shell. Or what is it usd for?

Also when I use A trigger and I get in my game I cant go through the trigger. why?

PS: I just want to thank all those people who helped me in my last First fourm..... hope you can help me here

caulk sky is for when you want to texture the sky with your fog... caulk sky youd put on like an other skybox texture and you have to have a farplane value to use caulk sky...
the trigger brush has to have a trigger texture(you know that right?) and the if you cant go through it you either have a shader problem or you un-checked "non-solid on the surface properties window (press 's' if youv didnt know)that should fix it..