FWIW...The real problem with posting Beware of Dog signs is it tells your biggest enemy (your insurance company) that you have a dog that might bite.
Insurance companys routinely cancel Home Owners Insurance or deny coverage if you have a certian "dangerous" dog breeds, such as Pit Bulls, Doberman, German Shepherds, Akitas etc.
I had my home owners insurance renewal denied by Allstate because I had a Doberman. I had a sign posted that showed a Doberman and said "I can make it to the gate in 2.3 seconds, can YOU" that one of their claims reps saw when he checked out some damage to my house from a tree that fell on it. The reason stated on the denial was..."Dangerous Dog Breed".
gb