Question: What is the maximum number of signs a city can have?
Answer: 50

Question: What is the maximum number of letters per sign?
Answer: 23

Question: How do I change what a sign says?
Answer: Create another sign on the same tile. It will replace the old one.

Question: How do I destroy a sign? The bulldozer won't erase it.
Answer: Create another sign on the same tile with no words in the sign. The sign should go away.

Question: How do I move a sign?
Answer: Delete the sign as described above, then create the other sign somewhere else.

Advice: If you are going to share your cities via e-mail, ftp, uploading to a bulletin board, etc., you may want to "sign your city" by putting a sign up with your name or e-mail address on a sign. Don't put your phone number or address on a sign.