Writing a Signature in a map's .bsp

I've noticed this before, but I never cared about it until now.

I see that many Beta 1.1 mappers "signed" their maps, as it is present in loading the map:



How do I go about doing this?

I wanted to do the same things on my models, but just on the bottom, have it say it my name, so no one can say they did it (unless they had experience)


Although I do know that someone on here (whoever made Zombie Island) just had a box that was textured saying he made it

Not good enough! I dont want to waste precious brush space

Also TIL that the copy of Verruckt I have is from Beta 1.2. How the heck did that happen?

It's under Map>Map Properties iirc, don't have Jackhammer open but it should be Text on Entering World.