All three of my dogs wear collars with 3 tags on it. 1) Dog's name and phone number. 2)Rabies tag which has the vet's name and number. 3) Microchip tag with microchip number and phone number.
Even my cat has a tag with her name and phone number on it and she is an outside cat!
I usually walk my dogs with a harness but the collars are still worn. When Harley (6mths) tries to chew on Tessa's(10mths) I just give a firm NO and he stops.
Tags are the first line of defensive in reuniting pet and owner!