If anybody know the secret and want to tell, hurry up.
I know the entity advertisement is made from a patch and is made non-solid in-game.
I know there's a key cellId and value is a number.
But don't know the key usage and what values are the valids.
If the compiler adds the key and valid value automatically, I should know it. I'm using Radiant 1.6.3

Geometry along the advertisement, editor shot

CellId value