I used to put on collars “ dog is not lost, leave alone” then name and number. That was before gps collars but still had people picking them up every now and then. I used to also always freeze brand ears of dog that I knew I would keep for long time. A funny or maybe not so funny story I sold a dog for a lot of money at 6yrs old. Five years later a guys calls me and said he bought a really nice cat dog for 4K and it had my initials on its ears. Said the dog was 7 . He sent me a pic and I look up the birthdate and told him unfortunately the dog is almost 12 and probably done. He called the guy back and got his money back and kept the dog as a box dog until she died. So the freeze brands at least helped out someone.