An identification tag can contain any kind of contact information needed to reach you quickly and easily. In this day and age when a fully functional prepaid cellular phone can be purchased alongside ones groceries for a minimal cost, a person discovering your lost dog can contact you almost instantaneously no matter where you are.
Animal control centers will also be able to let you know if they have rounded up a pet who strayed too far outside of the fence.
Dog tags are also fast. Identification numbers as tattoos or implanted microchips are wonderful ideas for permanent identification. However, these methods need to be read. Microchips require specialized equipment to read. Fur grows over tattoos. Once the information is found and read, it needs to be checked against a database.
Alternately, a pet tag will be easy to find and read. Your contact information will be visible in plain language that will help the other person reunite you and your dog.
Finally, a person who locates your pet can be enticed to contact you even more quickly if you openly - and honestly - offer a reward and post notice of it on your dog's tag.
